ARCHIMEDES SCREW	(Figure 3)

     According to G. Gregory's Dictionary (1816), "of all the machines the ancients invented to raise water it appears that Archimedes Screw was the most curious." In the seventeenth century this machine was modified in an attempt to develop a perpetual motion machine by causing the descending water from the top of the screw to turn the screw and thus in turn to raise the water. The base is twenty inches long. This particular model was made by Benj. Pike, Jr., of New York.
We have seen Pike's Illustrated Catalogues of Optical, mathematical and Philosophical Apparatus in the 1848 edition in the New York Public Library and 1856 edition in the Oberlin College Library.

ARTIFICIAL EYE	(Figure 4)

     An apparatus made to illustrate the application of spectacles for long and short sight. The lenses for near and far sightedness are missing from this particular instrument.
     An early Boston catalogue (Ritchies Illustrated Catalogue, Boston, 1860) lists this device at $9.00.

ARTIFICIAL EYE	(Figure 5)

     This is an unusual model in that it has a normal lens, a near-sighted lens, and a far-sighted one which may, in turn, be placed in the front of the eye. Of course, the near and far lenses produce blurred images on the "retina" at the rear of the model, but there are corrective lenses which may be placed over the abnormal ones which will then restore the images to a sharp focus. The eye is completely dissectable and may be taken apart for storage in its case.
     This model was made in England by W. & S. Jones and cost $7.00. We have seen W. & S. Jones' Catalogues for 1827 and 1829.

ATWOOD'S MACHINE	(Figure 6)

     Atwood's machine was designed to illustrate the laws of falling bodies.
     This particular instrument was purchased in 1821 by Dr. Charles Caldwell from the famous firm of Pixii in Paris. The Widener Library at Harvard has a series of Pixii Catalogues.
     Note the mahogany column and the replica of a Grecian urn atop the instrument. This machine was made during a time when the classical influence still prevailed in natural philosophy. Occasionally the clock escapement and the pendulum, which are integral parts of this machine, were mounted separately on a wall nearby.
     Our records show that the original weights for this machine were lost and replaced by new weights which in turn have been lost.
     It is interesting to speculate that very likely this piece of apparatus was shipped from Paris by sailing vessel to Philadelphia, transported across Pennsylvania to Pittsburgh, floated down the Ohio River by barge to Limestone (Maysville), Kentucky, and then brought over-land to Lexington.
     Figure 6 shows a small corner of the present museum room in the basement of the Library Building. Part of a Leyden jar battery can be seen as well as one of the antiquated book cases now used as exhibit cases.

AURORA TUBE	(Not Illustrated)

     An apparatus, listed in the earliest catalogues, that is still listed in current catalogues.
     If a battery is discharged through a tube several feet long and nearly exhausted of air, the whole space is filled with a rich purple light. The sparks from the machine, conveyed through the same tube, exhibits flashings and tints resembling an aurora borealis.
     Sometimes the "Guinea & Feather Tube" is used as an aurora tube.

BALANCE	(Figure 7)

     A balance purchased from Charles Chevalier. The museum has another balance of similar type, but slightly smaller, and without the name of the maker.
     There was a succession of instrument makers by the name of Chevalier. Charles was the son and successor of Vincent, and Charles was followed in turn by his son, Arthur. The catalogues of Chevaliers are numerous, beginning in 1820, or perhaps, before, and continuing at least to 1863. The firm of Charles Chevalier not only had a Paris headquarters, but had a London branch.
     Many of the best examples of early philosophical apparatus were made by Chevalier. Chevalier Catalogues are not uncommon. We have seen them at the Boston Public Library and at the libraries of the Smithsonian Institution and the Franklin Institute.

BALANCE	(Figure 8)

     This instrument was bought by Dr. Robert Peter from Watkins & Hill, Charing Cross, London, on August 21, 1839. It is listed in Dr. Peter's notes as "Delicate Assay Ballance & Wts." and it cost 16 16 0. A good descriptive catalogue of Watkins & Hill apparatus was used in 1836.
     Some of the original weights are still in the drawer. There are small doors at the sides, the front panel can be lifted, and the entire casing can be removed from the balance.

BLOW PIPE	(Figure 9)

     While incomplete, enough of the apparatus remains to be of interest. Essentially the air is forced through the blow pipe (not shown) by a pair of reciprocating leather bellows. An elaborate series of standards, clamps, and joints are provided so that small retorts and evaporating dishes can be placed conveniently for heating. The blow pipe was connected to the bellows by rubber tubing.
     The bellows fit neatly in the bottom of a nicely made box, the other parts are stored in a tray which fits above the bellows. A well made sketch on thin paper showing the blow pipe in operation was found in the tray. The name of the maker is not given.

CAMERA	(Figure 10)

     Either a Fox Talbot Camera or an early copy of one. It measures 8-1/8 x 9-1/8 inches. The lens is 2 inches in diameter. The camera here on display is similar to the one photographed in the "Science Museum," London, 1957. The Science Museum camera is dated 1835.
     The following is quoted from page 245 of the "Reports of the Juries" (1852) concerning the 1851 Great Exhibition of London. "Whether the followers of Talbot will ever obtain a preeminence over those of Daguerre or vice versa, is a question for time to solve; at present, the two systems appear in the British Department of the Exhibition to be equally well represented; the followers of each, with few exceptions, laying claim to some improvement or peculiarity of manipulation...."

CAMERA LUCIDA	(Figure 11)

     An early type made by Spencer, Browning and Rust of London. Since the printed directions showed the instrument attached to a book, materials for the photograph were similarly arranged.

CHEMICAL SCALE OF EQUIVALENTS	originally: (Not illustrated) now: (Figure 158, right)

     This scale measures about two and three-quarters inches wide. The main body of the scale which bears the names of both elements and compounds is about nineteen inches long. This body of the scale is divided lengthwise by a sliding logarithmic scale numbered from 8 to 330.
     The face of the scale bears the following heading or title, "Improved Scale of/ Chemical Equivalents/ By Lewis C. Beck and Joseph Henry/ Albany 1828/ Second Edition." The reverse side is solidly printed with directions for the use of the scale. The directions start as follows, "The scale of Chemical Equivalents, the invention of which is due to Dr. Wollaston, is an instrument stamped with the accuracy and ingenuity of its author, and which has contributed in an eminent degree to facilitate the general study and practice of chemistry. The present scale differs from the original one, in the assumption of Hydrogen as the radix or unity."

CHROMATROPE	(Figure 12)

     The following is from an 1860 catalogue (Casella, L.P., "Illustrated and Descriptive Catalogue of Philosophical, Meteorological...," London, 1860.) "Chromatropes, producing beautiful revolving circles, etc., of colored lights infinitely varied; as exhibited at the Royal Polytechnic Institutions." These particular chromatropes have the largest glass circles of any advertised. Out of the original set of twelve, only five are in good condition. They are inscribed in India ink "Invented and painted by H. Childe." We also have several unnamed smaller ones (Figure 13).

CLAUDE LORRAINE MIRROR	originally: (Not Illustrated) now: (Figure 152)

     A black glass mirror that is sometimes called a landscape mirror. It was used "to facilitate the delineation of landscapes in perspective." Another catalogue states, "Obsidian, Claude Lorraine, or Landscape Mirror...for condensing landscapes in true perspective view, and imparting a soft shady tint to the natural colors; a most valuable acquisition for the artist." (Gall & Lembke. Illustrated and Descriptive Catalogue, Etc., New York, 1870.)

CLOCK	(Figures 14 and 15)

     This clock, as the statement from Philip Fall shows, was valued by him at $450.00. It was made by W. & S. Jones of London a century and quarter ago and today, when wound, keeps excellent time. The clock is designed to show sidereal time. The hours from 0 to 24 are shown on the lower dial, the seconds on the upper dial, while the outer sweep hand is the minute hand.

COLLISION APPARATUS	(Figure 16)

     An apparatus that has five positions on the upper bar from which balls may be suspended. Two balls from a collection of several were used for the purpose of this photograph. They may not be the original ones. This apparatus bears the name of B. Pike, Jr., 294 Broadway, New York.

COLOR WHEEL AND TOP	(Figure 17)

     These were used for the determination of the composition of colors. These items are in good condition except for considerable fading and discoloration of the colored paper. No name of maker.

CONDENSER OF EPINUS	(Figure 18)

     Frequently shown in the early catalogues, sometimes this instrument is figured with a glass plate between those made of brass. Each brass plate is equipped with a small quadrant electrometer. This instrument is in excellent condition, except that the index marker of one electrometer is missing.

DANIELL'S HYGROMETER	(Figure 20)

      An instrument for measuring the comparative moisture of the air. This hygrometer was first described in an article entitled, "On the new hygrometer," by J.F. Daniell, Esq., FRS and MRI. (Art XI in the Quart. Jour. Of Sciences, Literature, and the Arts. Vol IX, pp. 128-137. London, 1820.) The directions for the use of this instrument are also given by Negretti and Zambra (A Treatise on Meteorological Instruments, London, 1864). Daniell invented the electric cell in 1836 and also a pyrometer.
      This case for this instrument illustrates the fate of the cases in which the early apparatus were stored. The instruments having been stored in their cases and the cases locked the keys were lost. At a later time, the cases were carelessly forced open and often split and badly damaged.
     Our instrument was bought by Dr. Peter from Deleuil, Paris, in 1839.

DISCHARGER	(Not Illustrated)

     Also known as discharging rods. These were used to discharge Leyden jars, electric batteries, electric machines, etc. The one in the Transylvania Museum has just the right spread to discharge the large plate electric machine (Figure 23).

ELECTRIC BATTERY	originally: (Not Illustrated) now: (02-17) or (02-22)

     The samples in our collection show extremes in the range of elegance of construction of this common type of early apparatus. Each of our complete sets consists of nine jars.
     The battery of Leyden jars was used whenever it was necessary to increase the amount of electricity to be stored for use with electrical devices. The amount of electricity stored is proportional to the amount of foil surface. Not only can the number of jars in a battery be varied, but the capacity of each individual jar varied from a half-pint to a two-gallon size. As an example, Dr. Rees (New Cyclopedia, Phila., Vol. IX, pt. 2, plate 1) shows an electrical machine connected to a battery having three boxes of thirty-six jars for a total of 108 Leyden jars.

ELECTRIC CANNON	(Figure 21)

     A cannon made to be muzzle loaded and fired by an electric spark. It is mounted on top of an insulating glass rod and has a heavy leaded base. No name of maker, but may have been bought from Pixii under the name of "Volta's Cannon" for 36 francs.

ELECTRIC-MAGNETIC MACHINE	(Figure 19)

     An apparatus for getting magneto-electricity (p. 296, Ohmsted's "Introduction to Natural Philosophy," 1870).
     Bought by Dr. Peter of E.M. Clarke, London, in 1839 for one pound, fifteen shillings. Machine is incomplete. The museum has this machine and the case and the parts of a second one.

ELECTRIC SPORTSMAN	originally: (Not Illustrated) now: (Figure 122)

     The following quotation is from Watkins & Hill (A Descriptive Catalogue, etc., London, 1836): "This amusing apparatus consists of a carved figure represented in the act of shooting, and a Leyden jar having two wires of different lengths applied to its cap. On the end of the longer wire small pith birds are suspended by threads. When the shorter wire is within striking distance of the muzzle of the sportsman's gun, and the inside of the jar is in communication with the prime conductor of the machine in full action, the birds fly off, but the instant a discharge takes place the pith birds fall as if shot."
     Our sportsman lacks his gun and is displayed without the Leyden jar.

ELECTRICAL MACHINE	(Figure 22)

     This is an example of an early model. In machines of this type frictional electricity is produced by the revolving plate rubbing against a leather pad. No name of maker.

ELECTRIC MACHINE	(Figure 23)

     A common part of generator of static electricity. This particular machine was bought over a century ago at a cost of $195.00. It has unusually large hollow brass prime conductors. The extremities of these conductors end in two bows which, in turn, have sharp points to facilitate the passage of electricity from the large glass plate, but all other parts are rounded in cylindrical or spherical form, without edges or points, in order that the electricity produced by the machine will not be dissipated. This machine has a purple glass thirty-three inches in diameter.
     Most nineteenth century texts on natural philosophy and many catalogues of the same period have figures on machines of this type. A good general discussion of important persons in the development of electricity is given by Bern Dibner (Early Electrical Machines (1600-1800), 1957). He includes in his remarks descriptions of early experiments and apparatus. On page 42 of his account is a good photograph which resembles very closely this machine in our collection. Dibner says that his was the type of machine used by Nicholas T. de Saussure, professor of Geology and Mineralogy at the University of Geneva. The machine was built by Dumotiers [z] Frères, Paris.

ELECTROMETER-PITH BALL TYPE	(Not Illustrated)

     This apparatus consists of a tall green glass rod mounted on a brass base. The rod is tapered and curved with a hook at the extreme end for the reception of the pith ball. Dr. Peter's notes show that this machine was purchased from Pixii, Paris, in 1839 for 45 francs.

ELECTROSCOPE (ELECTROMETER)	(Figures 24 and 25)

     These are two samples of early types of electroscopes of which there were several varieties. Figure 24 represents Bennett's Gold leaf electrometer, while Figure 25 is a condensing electrometer. Both of these are described by Robert Hare (Compendium of the Course in Chemistry etc., Phila., 1836).
     Electroscopes such as these with wide flat canopies instead of knobs, also can be used as electrical condensers.
     No makers' names.

EUDIOMETER by HARE	(Figure 27)

     Robert Hare was Professor of Chemistry at the University of Pennsylvania at the time he designed this piece of apparatus. He called it an Aqueous Sliding Rob Hydro-Oxygen Eudiometer. It is illustrated on page 223 of his book (A compendium of the Course of Chemical Instruction in the medical Department of the University of Pennsylvania. Third Edition, by Franklin Bache, M.D., 1836, Philadelphia).
     For contrast in the construction of eudiometers, Figure 43 (center) shows one designed by Volta. A good description and figure of this instrument is given as fig. 11, Plate 2, by M. LeBaron and J.L. Thenard (Traite de Chimie, Bruxelles, 1836).

EOLIPILE (AEOLIPILE)	(Figure 26)

     An early dictionary (G. Gregory, 1816) describes this as follows: "...a hollow metalline ball, in which is inserted a slender neck or pipe; whence after the vessel has been partly filled with water, and heated, issues a blast of vapour with great vehemence.
     "The aeolipile is sometimes placed in a small carriage, and a cork thrust into the extremity of the pipe. When the vapour is sufficiently heated, it rushes out the cord in one direction, while the carriage moves the contrary way."
     The spirit lamp is missing from this machine. The spherical brass boiler is two and a half inches in diameter. In the list of apparatus purchased from Pixii there is given, "Eolipile on wheels - 45 francs." The name Aeolipile is also given by Edw. H. Knight (American Mechanical Dictionary, 1876) to Hero's Engine. But in Hero's engine the steam issued from two bent arms, and by reaction rotated the sphere to which the arms were attached.

EQUILIBRIUM TUBES	(Figure 28)

     This apparatus is designed to illustrate the principle that in tubes or vessels of any shape or size (larger than capillary) which communicate with each other, water will rest only when its surface is at the same level in them all. Some of the tubes of this instrument are missing. The base measures 18 inches long.

FOUNTAINS IN VACUO	(Figure 29)

     These two fountains are for use with vacuum pumps. They are made of very heavy glass. The taller one is almost four feet tall and it will throw a spray of colored water. The shorter tube is designed to throw a fountain of mercury.

FRICTION BLOCKS	(Figure 30)

     "Place a block on an inclined plane, whose angle can be varied, and then find the relative friction in different cases, by the largest inclination at which it will prevent the block from sliding" (from an early textbook). These blocks are sometimes listed in catalogues as "Inclined plane and car, with graduated quadrant."
     Friction can be evaluated by the use of weights acting on a block by means of a cord and pulley.

GEOMETRIC (AND OTHER) MODELS	originally: (Not Ilustrated) now: (02-23) or (02-24)

     The museum has two trays of solid glass models of various geometric forms. These two trays still contain a total of twenty-nine pieces. They probably were used in crystallography. There is also a third tray which contains a few odd shaped glass pieces. These probably were designed to be used with polarized light. The museum has a miscellaneous collection of wooden geometric models.

GLASS FIGURES	(Figure 31)

     This is a set of glass shapes mounted in mahogany sliders. The glass is one-half inch thick, sometimes is single and sometimes in sections. The glass is unannealed and consequently when viewed by polarized light shows rainbow colors along the lines of internal tension. These are in excellent condition. Made by W. & S. Jones, London.
     The museum also has several much thicker glass shapes mounted in unvarnished wooden holders (not illustrated).

GLASS PIERCER	(Figure 32)

     Probably the apparatus described in "Perce-verre-èlectrique" in Larousse du xxe Siècle. The few pictures in the "Grand Dictionnaire" of Larousse for the nineteenth century edition are also reproduced in the edition for the twentieth century. This particular piece of apparatus measures six and one-half inches along the base. Figure 515 in D. Lardner (Hand-book of Natural Philosophy, Phila., 1853) shows this apparatus.

GONIOMETER by WOLLASTON	(Figure 33)

     The goniometer is an instrument for measuring the angles of crystals. It was bought in August 1839 by Dr. Robert Peter from E.M. Clarke, London for 3 13 6. An early discussion of goniometry can be found in Gregory's Dictionary, 1816.

GUINEA AND FEATHER TUBE	originally: (Not Illustrated) now: (03-01)

     This is common piece of apparatus to illustrate obvious principles of falling bodies in a vacuum. The tube in our collection stands seven feet tall. Such tubes can also be used as aurora tubes.

HEAT CONDUCTION APPARATUS	(Figure 34)

     The rods are of different substances, metal and otherwise, and of the same length. If marbles of the same weight are attached by wax to the ends of the rods and the vessel filled with boiling water, the marbles will fall at different times depending on the heat conductivity of the different rods. This is sometimes referred to as a conductometer. Frequently the trough for the hot water is supported in a horizontal position rather than at an angle as in this instrument.

HEAT REFLECTORS	(Figure 35)

     These reflectors can be placed from ten to fifteen feet apart, and then when a red hot iron is placed at the focal point of one reflector it will cause an inflammable substance, such as phosphorous, to be ignited at the focal point of the other reflector. These reflectors are mounted on tall wooden standards.
     We have two sets of these reflectors, (such as the pair in Figure 36) which are mounted on short metal standards and are designed to be used on a table or bench.

HELIOSTAT	(Figure 37)

     This optical instrument was used to fix the sun's image for various kinds of observations needing a bright light. The mirror is four and one-half inches in diameter. It is in good working condition.
     Knight (American Medical Dictionary, New York, 1876-7) credits Gravestand with inventing this instrument in 1719. Various improvements were added by others.
     While there is no name of the maker on this instrument, it is included among the London purchases made by Dr. Fall. He gives its value as $42.00.

HOPE'S APPARATUS	originally: (Not Illustrated) now: (05-03)

     Designed to measure the expansion (density) of water at different temperature. It is pictured as No. 427 (p. 25) "Appareil pour de Maximum de densit‚ de l'eau" by M.M. Breton Frères (Catalogue, Paris, 1859). It consists essentially of a large glass cylinder (15 x 3¬ inches) on a footed base. About midway of the height, the cylinder is encircled by a copper through. Both above and below the cylinder is pierced by holes. Ice is placed in the copper trough and thermometers are inserted in the holes in the glass cylinder. It can be shown by experiment that the maximum density of water occurs at 4 C.
     Hope (1766-1844) was an English chemist born in Edinburg.

HYGROMETER	(Figure 38)

     A portable model (with refinements) of the Saussure type, It was bought by Dr. Caldwell of Pixii, Paris. This particular hygrometer, according to the catalogue descriptions, is activated through employment of a human hair. Vol IX (p. 35 and plate CCXLVII) of the 3rd edition of the Encyclopœdia Brittanica refers as follows to Saussure's Portable Hygrometer, "Apparently the fixed (great) and the portable hygrometers were first described by Saussure in an article (essay) on Hygrometers published in 1783. Suassure was a professor of philosophy at Geneva. The human hair is the activating agent in both types."
     Our instrument is complete and in good condition except that the original silk cloth panels are missing.

HYDROMETRIC BALANCE	(Figure 39)

     Charles Chevalier was the maker.
     "This is an instrument for indicating the relative density of the air, and the consequent chances of rain or dry weather. It consistes of a balance, from one arm of which is suspended a brass weight, and from the other a large hollow sphere.... If the air becomes heavier, the large sphere, displacing more air, will become buoyant and ascend." (Edw. H. Knight, American Mechanical Dictionary, New York, 1876-77.) It also was used to demonstrate that air has weight by placing the balance under a bell-jar of a vacuum pump. When the air was partially exhausted from the bell jar, the sphere containing air dropped.

HYDROSTATIC PARADOX	(Figure 40)

     Apparatus used to illustrate the principle "that a quantity of fluid however small may be made to counterpoise a quantity of fluid however large." The experiments using this apparatus, or one similar to it, are described in almost every early treatise on natural philosophy. The cylindrical water contained is in position. The funnel shaped container is threaded so that it can replace the cylindrical one.

INDUCTION CYLINDERS	(Figure 42)

     These cylinders or conductors are supplied with hooks to which pith balls are attached to serve as electroscopes. These brass cylinders have not been refinished.

INDUCTION MACHINE	originally: (Not Illustrated) now: (03-12)

     This instrument, known as the Toepler-Holtz Electrical Machine, develops electricity with great rapidity without friction. "Toepler constructed as influence' (induction) electric machine in 1865. Holtz constructed many influence machines between 1864-80" (11th Edition, Encyclopedia Brit., Vol. IX).

KINNERSLEY'S THERMOMETER (Air or Electric)	(Figure 43, right)

      An apparatus designed to show the expansion of air when an electric spark is passed through it.
     Probably bought by Dr. Peter from Pixii, Paris, in 1839 for 18 francs. Electrical-Air-Thermometer "is an instrument contrived by Mr. Kinnersley of Philadelphia for the purpose of observing the effects of electrization upon air, and with this instrument Mr. Kinnersley made several experiments which he describes in a letter to Dr. Franklin, dated March 12, 1761."
     This figure also shows Oersted's Apparatus (left) and Volta's Eudiometer (center).

LUCERNAL MICROSCOPE	(Figure 44)

     The objects to be examined by the Lucernal microscope are illuminated by the light of a lamp or candle. In our instrument the arm for the lamp is in place but the lamp is missing. With this particular instrument there was purchased a large collection of natural history objects -- plant, animal, and mineral. Some of these objects are for transmitted light and some are in wooden troughs for reflected light.
     The following directions (in part) came with the microscope:

     First light the Lamp with the best oil and cotton for a steady and good light. Then slide the microscope firmly on its case. Slide out the small wood slider at the top end of the microscope cone, and push up the Shutter. Screw on the large end of the sliding brass tube to which fasten the sliding sight piece. Slip on the stage bar the two condensing lenses, the smallest one first. For opake objects place the ebony slider at the spring stage. Your face before the large condensing lenses and the roughed glass taken out, place the lamp on the left side of the microscope the flame being at the height of the object. Place the jointed adjusting handle at the right hand pinion and the plain one through the ring at the left hand side of the cone to the opposite square. [Note: In the photograph the handles are reversed.]
     A beginner should use No. 6 magnifyer, an object being placed directly opposite to the magnifyer, move the light and condensing lenses so that the light may be fully and strongly condensed on the object. Now place your eye to the hole of the sight piece opposite to the centre of the large lenses and move the tube inwards or outwards, and the sight piece up or down, until you see the lenses filler, or diffused over with a vivid light. Move the tube of the magnifyer until the objects appear nearly distinct, then with your eye at the sight hole turn gently the stage adjusting rod until the objects appear the most distinct and best defined as possible. The effect will be very brilliant and striking the roughed glass being placed before the lenses, will receive the images of the objects on its surface and will enable a person to copy their outlines with a pencil.

(Title Page)

List/ of the / Transparent/ and Opake/ Objects/ for the / Improved/ Lucernal/ Microscope/ by/ W. & S. Jones/ 1839

(Page 2) Transparent objects in the six small Ivory Sliders

     No. 1. Hair of a Mouse, Ditto of a Bat, Down of the Tussock Moth, Do of the Noctua Nupta. No. 2. Tongue of a Bee, Sting of a Ditto, Claw of a Ditto, Wing of a Wasp. No. 3. Eyes of a Spider, Jaws of a Ditto, Leg of Ditto, Wings of Cicada.

(Page 3)

     No. 4. Tongue of a butterfly, Eye of a Ditto, Antena of a Moth, Legs of Ichneumon fly. No. 5. Tongue of the house fly, Eye of a Ditto, Farina of Holly hock, Wing of a Cricket. No. 6. Scale of a solefish, Ditto of a Dace, Seed Vessel of Sorrel, Field Spider.

(Page 4)

     Transparent Objects, Sections of Wood in the 6 large Ivory Sliders.
     No. 1. Cane, Dwarf Almony, Aucaba, Sycamore. No. 2. Broom, Yellow Jessimin, Pyrus Japonica, Peach. No. 3. Willow Root, Willow Branch, Snow Ball or Guelder Rose, Spanish Chestnut.

(Page 5)

     No 4. Bay Tree, Cedar Tree, Clove, Hypericum. No. 5. Gum Cistus, Buckthorn, S. American Rush, Nectarine. No. 6. Pear tree, Sumach, Raspberry, Mountain Ash.

(Page 6)

     Transparent Objects in the 3 large Boxwood Sliders
     No. 1. Skin of a Spider, Ditto of a Snake, Legs of a Dragon fly, Dissected leaf, Wings of a bee. No. 2. Bloom of Grass, Wing of Grasshopper, Do of Ichneumon fly, Do of the Currant moth, Do of the Ephemera.

(Page 7)

     No. 3. Wings of the Dragon fly, Ditto of Libellula, Do of the Hemerobius.

(Page 8)

Objects in the 18 Ebony Sliders   (Figure 45)
No 1. Small English Insects, Bronze Carabus Beetle, Small Oak Ciculios, Asparagus Beetles. No. 2. Gold Circulios, Green Chrysomela, Cantharides, Spanish Fly, Blue Chrysomela. No. 3. Cincindella Comprestic, Part of Wing Case of Ditto, Corslet of Diamond Beetle, Wing of Buprestis Chinese Fly.

(Page 9)

No. 4. Feather of a Turkey, Wing of a Butterfly, Wing of a Locust, Feather of a Peacock. No. 5. Mixed Poppy Seed, Mignonette Seed, Carraway Seed, Parsley Seed. No. 6. Burnet Seed, Cornbottle Seed, Thornapple Do, Sn. Fain Do. No. 7. Small English Shells, Variety of Ditto, Small Trochus, Nerita Verginia.

(Page 10)

No 8. Screw shell & Section, Nautilus Pyrula, Spotted Columbellas, Small Pecten. No. 9. Small Crab, Sea Echinus, Scales of Perch, Skin of Dog fish. No. 10. Red Coral, White Coralline, Gorgona Sea Weed, Madrepora.

(Page 11)

No. 11. Dissected leaf, East India Pearls, Common Scotch pearls, Oolite or Roe Stone. No. 12. Crushed Minerals, Small Emeralds, Do Garnetts, Iron Sand. No. 13. Tinstone Ore, Gold Colored Mica, Lepidolite, Crystallized Bismuth.

(Page 12)

No. 14. Galena, Sulphuret of lead, Green phosphate of lead, White Carbonate of Do, Scum of lead. No. 15. Cubical Iron Pyrities, Oxydulated Iron Ore, Mundic, Iron pyrites, Specular Iron Ore. No. 16. Orpiment, Native sulphur, Realgar Sulphuret of Arsenic, Cinnabar Sulphuret of Mercury, Steel grains Iron Ore.

(Page 13)

No. 17. Malachite Green Carb of Copper, Red Oxide of Copper, Peacock Copper Ore, Native Copper. No. 18. Spicular Antimony, Lapis Lazuli Ultramarine, Silver Ore, Grains of Platina.

MAGDENBURG SPHERES	(Figure 46)

     These are designed to illustrate the pressure of the air on the halves of the sphere after the inner air has been exhausted by a vacuum pump. These spheres seem to be an improvement on the earlier Hemispheres of Otho Guericke, the inventor of the air pump.
     Two of the spheres can be joined in tandem, while the other rests on its own base. No name of maker.

MAGNETIZED BLOCKS	(Figure 47)

     As the figure shows there are four numbered blocks and a revolving numbered indicator in which one number at a time appears. When the indicator is placed over a block the number in the window of the indicator and number on the block correspond.
     This is one of several "Amusemens de physique" based on the principles of the magnet. Sometimes they were used to tell fortunes, etc. An explanation of these blocks is given in volume 8 by M. Le Noir (Encyclop‚die M‚thodique et M‚tiers M‚chaniques. First volume dated 1792).

MARCET'S STEAM APPARATUS	(Figure 48)

     This apparatus was designed to show the relationship between pressure and temperature. It works on the principle of the pressure-cooker or the autoclave. It consists of a bomb-shaped body of heavy iron to which are attached a barometer, a thermometer (missing on this example), and a stopcock. This instrument is listed by L.O. Casella (Illustrated and Descriptive Catalogue, Etc., London, 1860).
     Bought in London of E.M. Clarke (August, 1839) for 3 13 6

MICA PICTURES FOR POLARIZED LIGHT	originally: (Not illustrated) now: (03-21)

     Six handsomely made mica pictures for polarized light. These are mounted between glass rectangles, the whole neatly framed in mahogany. They measure 6.5 x 7.25 inches. The pictures include such usual objects as a parrot, a bunch of grapes, a window, etc. The box in which they are stored has a deeper side for two somewhat larger pictures which are missing.
     The museum has also many smaller pictures in sliders. They are of common objects such as flowers (thistle, forget-me-not) and conventional designs. These were favorite items in the early catalogues.

MICROSCOPE	(Figure 49)

     This instrument was made by R. & J. Beck, London, probably before 1870. It has a reasonably modern look and is in good condition.

MICRO AQUARIA	(Not illustrated)

     A set of eight thin glass troughs to be used with the low power of the projecting (lime light) microscope (Figure 50). These aquaria are of varying thickness from front to rear but all less than one-quarter inch. Six of them measure roughly 4-3/4 x 1-3/4 (inside dimension) while two are much smaller.

MICROSCOPE (Jones Most Improved)	(Not illustrated)

     A compound microscope, known in its day as "Jones most improved," is a complete instrument with insect boxes, fish through, auxiliary magnifiers, etc. It represents the peak of compound microscopes during the early nineteenth century. The microscope is now in only fair condition and the mirror is missing.
     In the 3rd Ed. of the Encyclopedia Britannica Brit., Vol XI, p. 715, there is an article which shows that our Jones Most Improved Microscope had its start in an instrument first known as Martin's New Universal Compound Microscope. We also are told that a Mr. Jones of Holborn, London, suggested several alterations. The figure of this microscope as altered by Mr. Jones shows that it is still not as useful as the "most" improved model, which must, of course, have been a still later model. The third edition of the Britannica was published before the turn of the 19th century and our microscope was undoubtedly made several years later.

MICROSCOPE (Lime-light)	(Figure 50)

     This is the most complete of the three cal-oxyhydrogen microscopes which were purchased by the early University. We still have a large collection of objects made to be viewed with the aid of this particular apparatus. The microscope illustrated was made by W. & S. Jones of London. The other two were made by E.M. Clarke, also of London, and by McAllister of Philadelphia.
     Perhaps an interesting feature of this instrument us the housing on top of the tripod in which was generated the limelight. The tripod support stands about five feet tall and the housing measures 15 x 12 inches. The complete instrument with its objects for study were valued by Dr. Fall at $910.00.

MICROSCOPE (Cal-oxyhydrogen "lime-light")	(Figure 51)

     An early sketch showing the way in which the lime-light projector was made ready for use. One of the bellows was filled with oxygen, the other with hydrogen. The pressure exerted by the weights was sufficient to force these gases from the nozzles within the hood. Knight's Dictionary (1877) describes the Oxyhydrogen Lamp as an improvement over the Oxycalcium light in these words, "one in which streams of oxygen and hydrogen in regulated quantities are commingled, the resulting flame being directed on a ball of quicklime and forming an extremely bright light; now used very largely by lecturers on science to illustrate phenomena, and by exhibitors to project pictures upon a screen."

MICROSCOPE SLIDERS	(Figures 52 and 53)

     These are a few of the many objects in the Transylvania collection. Each specimen of plant or animal is preserved in Canada Balsam between plates of glass and then these are put in hardwood frames. They then were used for projection by means of a cal-oxyhydrogen microscope, which in reality was a type of magic lantern using "limelight."
     There are twenty-three sliders with unvarnished wooden frames made with mitered corners. The outside dimensions of these measures 151 x 56 mm. The identifying legend is written on the frame in India ink. There is no name of maker for this series.
     The larger series of 72 sliders was made by W. & S. Jones, 30 Holborn, London. These are the sliders illustrated. The wooden frames, usually of varnished mahogany, measure 185 x 62 mm. The central openings which contain the specimen vary in size and shape depending on the size and shape of the specimen. Several (11) of the sliders have been crudely cut down in recent years, presumably for the purpose of projecting them in a modern micro-projector. The fate of the eleven slides emphasizes the necessity of separating old from contemporary apparatus.

PIEZOMETER or OERSTED's APPARATUS	(Figure 43, left)

     This is an instrument for measuring the compressibility of liquids.
     We have only one example of this interesting device and it is not complete since it lacks the inner thermometer, the bulb, and the tube. The exterior tube is made of exceedingly heavy brass and glass, and weighs about 20 pounds. Hans Christian Oersted (1777-1851) was a professor at Copenhagen. He is also credited as the real discoverer of the magnetic properties of electric currents.
     This apparatus probably was purchased by Dr. Peter from Deleuil, Paris, in July 1839 for 65 francs.

PLANETARIUM, WITH LUNARIUM & TELLURIAN	(Figures 54 and 55)

     These came to the College through the Philip Fall Purchase, and originally cost $210 when purchased from the famous London firm of W. & S. Jones.
     It should be noted that there are but seven planets shown and that Jupiter has but four moons. A good description of these three instruments is given by George Dams (Philosophy, Vol. IV, Phila., 1807). Some indication of their age is revealed by the inscription on the small globe of the tellurian which read, "Published by J.W. Carey, Strand, Apr. 1, 1791."
     In Vol. XXVI of Rees' Cyclopedia under "Orrery" is a description of Mr. Benjamin Martin's Orrery or Microcosm -- "but though the microcosm was, perhaps, never constructed as an appendage of a clock, yet it laid the foundation of our more modern planetaria, tellurans, and lunaria, which constitute the orrery in three parts, as constructed by the workmen of Messrs. Adams, Jones, etc."
     These particular instruments are listed in the 1829 catalogue of W. & S. Jones at 37 16 0. One figure (54) shows planets in place as a planetarium. The other figure (55) shows the planets removed and the tellurian in place. The lunarium can also be placed on the central axis, as illustrated on the title page.
     An account of an earlier version (without the tripod support) of this planetarium can be found in William Jones (The Description and use of a new Portable Orrery, etc., London, 1794). An appendix lists optical, mathematical, and philosophical instruments made and sold by W. & S. Jones, at their shop, No. 1355, next Furnival's Inn, Holborn.

PRISMS	(Figures 56 and 57)

     In this set are two glass prisms on adjustable brass stands, a hollow prism on a brass stand, and a fluid prism. With one exception these are the only prisms left to the present time out of the considerable number which were purchased during the early days of Transylvania university. In fact, among the items purchased from Fall there is listed "A hollow prism $6, Two glass prisms, $9." And among the items purchased by Peter from Pixii we find, "2 prisms mounted, 1 hollow, 70 fr." Since no makers' names appear on the instruments, they cannot be fully identified, but since the three stands are of similar brass and of similar construction they would not appear to be those mentioned by Fall.
     A fifth prism not illustrated is part of an unknown apparatus. The prism is rather large and slightly arced. The prism is mounted on top of a tall (30 inches) wooden tripod and it (the prism) can be revolved on its long axis.

PUMPS	(Figures 58 and 59)

     These were made by Charles Chevalier who made the large vacuum pump (Figure 80). They are designed to accomplish three types of action -- suction, elevation, and forcing. We would speak of them as lift and force pumps. The larger pump (Figure 59) has glass receptacles and other parts which are interchangeable. The catalogue of Chevalier calls them "très beau modelé" and lists them at 345 francs. A very good account of pumps, etc., with many experiments fully described, is given by N.B. and D. Chamberlin, (A Catalogue of Pneumatic Instruments, Etc., Boston, 1844). This catalogue also gives good explanations of the use of attachments for vacuum pumps. N.B. Chamberlin (Descriptive Catalogue, Boston, 1855) mentions, as does almost every nineteenth century catalogue, the hydrostatic paradox (Figure 40).

PYROMETER (HORIZONTAL)	(Figure 60)

     Listed in the Philip Fall purchase, this instrument was valued at $60. The drawer contains bars of various metals. The rectangular water tank through which the bars pass was heated by spirit lamps one of which is missing.
     A page of directions from W. & S. Jones for use of this apparatus reads as follows: The first lever is as 10 to 1, the second as 5 to 1. 10x5=50, that is 1.50 of an inch of motion be communicated the first lever will produce on inch of motion to any point in the circumference of the second, there being 20 teeth in on inch and 10 teeth in the pinion in the center 20 teeth in the circumference of the second lever will produce two revolutions in the first pinion, the Dial plate is divided into 200 equal parts, 2 revolutions of the pinion is equal to 400 of these divisions and 400x50 shows to 1/20,000 part of an inch is seen in each division of the Dial plate -- The bar having expanded 1/10. The divided arc on the face registers the number of revolutions the long hand has made, which never exceeds 6--.

QUADRANT	(Figure 61)

     This quadrant, although the name plate is missing, appears to resemble closely the one figured in plate CCCXLI fig. 65 (3rd Edition, Encyc. Brit. 1788-97) as Hadley's Quadrant. Quoting from page 724, "Hadley's quadrant is the chief instrument in use at present for observing altitudes at sea. The form of this instrument, according to the present mode of construction, is an octagonal sector of a circle, and therefore contains 45 degrees; but because of the double reflection, the limb is divided into 90 degrees."

RECEIVER	(Figure 62)

     Designed to illustrate to Torricelli experiment which shows that the weight of the air will support a column of mercury to a height of 29-30 inches. Apparently at some time in more recent years a new container for the mercury has been substituted for the original.

RECEIVERS	(Figure 63)

     These are for use with vacuum pumps. Each of the receivers was equipped with two barometers.
     There are other receivers of other shapes and construction in the collection besides those in the figure. Some of the others are of the "sliding rod" type as the one shown with the vacuum pump in Figure 80.

REVOLVING ARMATURE ENGINE	(Figure 64,center)

     The center figure shows this engine. One of the horizontal bars on the armature is missing. We have no data on the name of the maker or of the purchase, but it is described in Benj. Pike's 1848 catalogue. This engine and magnetic beam engine (Figure 65) are examples of simple apparatus designed to show the relationships of magnetism and electricity.
     The other two instruments in Figure 64 also are designed to show similar principles. They apparently were made by the same maker as is evidenced by the sameness of the wooden bases.

REVOLVING MAGNET ON AXIS	(Figure 66)

     This instrument was purchased from E.M. Clarke, London, for one pound. Very likely it is designed to show that a magnet revolves on its axis when the magnet forms the conductor of electricity. This figure appears in Daniel Davis (Catalogue of Apparatus, Etc., Boston, 1848).

REVOLVING WIRE FRAME	(Figure 67)

     One of two instruments of this type in the Transylvania collection. In both the circular ercury troughs on the U-shaped magnets are of hard wood. The revolving wire in this nstrument consists of straight wires. This one is described and figured by Daniel Davis (A Manual of Magnetism, etc., Second Ed., Boston, 1848). In the other instrument (not illustrated) he wire frame consists of a spiral wire with two terminal points which dip into the mercury roughs. This so-called helical wire apparatus was devised and described by Francis Watkins Popular Sketch of Electro-Magnetism, Etc., London, 1828).

SAFETY LAMP	(Figure 68)

     Sir Humphrey Davy invented the Safety Lamp using wire gauze in 1816 and a year later it was in widespread use in the coal mines. (From Vol. VI, 11th Ed., Encyl. Brit.)

SEXTANT	(Figure 69)

     This sextant bears the name "Ramsden." It is certainly named for "Ramsden, Jesse, an eminent English mathematical and astronomical instrument maker...born 1735" (from Rees' Cyclopedia, Vol. XXX, pt. 2). This sextant fits on a tripod base which in turn has a ball and socket swivel joint. Special mention should be made of Ramsden's improvement of the sextant and of his famous machine for the accurate dividing of brass sextants. Ramsden also is listed (Vol. XIII, pt. 2) as one of the three distinguished persons claimed to have invented the plate electric machine.
     Another sextant is in the collection but it has no name of the maker either on the sextant or on the case.

SIMPLE MACHINES	(Figure 71)

     These model machines are designed to illustrate the mechanical principles of the lever, the wheel and axle, the pulley, etc. The taller frame equipped with the pulleys was provided with horizontal strings spaced an inch apart. These strings were attached to marked scales to the right and left. Since this photograph was made the scales and strings have been replaced.
     Considerable space in the textbooks of natural philosophy of a century ago was devoted to the explanation of these simple machine principles.

SPARKLING COLUMNS AND FLYER	(Figure 72)

     This is a device to show the passage of an electrical charge. The charge jumps the gaps between the pieces of foil making up the spirals within the columns. The foil spirals were glued to the surface of a glass tube which was inserted inside the larger tube of the column. The discharge of the current caused the pin-wheel flyer to turn. These were used in conjunction with the static electricity machine.
     The museum has two of these sparkling columns and flyer instruments. Each is in perfect condition.

STAGE FOR DANCING FIGURES	(Figure 73)

     Pith figures are caused to dance when placed between the electrified lead foil stage and the electrified upper brass plate. This apparatus is sometimes listed in the catalogues as "Theatre pantin with glass pillars for dancing figures."
     Except for some deterioration of the lead foil stage this apparatus is in good condition.

STANDPIPE (JETS)	(Figure 28)

     Designed to show the relationship between the depth of a fluid and the velocity of its discharge.
     "When the aperture is small, compared with the breadth of the reservoir, the velocity of discharge varies as the square root of the depth." From an early text on Natural Philosophy.

SYREN	(Figure 74)

     "The syren is an instrument by which a series of air puffs are made to produce a musical sound, and by which the number of puffs made in a second are registered.
     "By simple artifice, the air which gives the sound is made to turn the disk. This is done by making the holes through the plate oblique instead of vertical." From Cooley's Natural Philosophy.
     In this instrument the slanted holes are in a revolving horizontal disc in the top of the brass cylinder. Apparently it is of the Caquiard-Latour type of about 1820.

TELESCOPE	originally: (Not Illustrared) now: (Figure 136)

      A very complete instrument. It has both astronomical and terrestrial eye glasses. It should be described technically as a five-foot, four-inch aperture, achromatic, refracting telescope. It is equatorially mounted.
     Compete instructions for the operation of this instrument were sent with it and are extant. In use today it shows with great clarity four of Jupiter's moons and resolves many of the double stars.

THERMO-ELECTRIC PILE	(Figure 75)

      This is also knows as a Thermo-electric battery.
     "An instrument composed of a number of alternate bars, generally of bismuth and antimony, by which small changes in temperature are rendered sensible by the production of an electric current, the presence of which is shown by means of a galvanometer." (Brande and Cox, "A Dictionary of Science" 3 vols. Rev., 1875.) This instrument was first constructed in 1834 by Nobili. It was designed for experiments and demonstration on heat and electricity, and is often used in conjunction with heat reflectors. This pile cell is hinged and can be raised or lowered.
     This particular apparatus bears the inscription "Elliott Bros. London, No. 355." One similar to it appears in the 1895 catalogue of his manufacturer.

THERMOSCOPE OF RUMFORD	(Figure 76)

     This is a differential thermometer and also is known as Leslie's differential thermometer. Purchased from Deleuil, Paris, in 1839 for 14 francs. The printing which shows the scale and the name of the maker is disappearing as the paint chips off.

THUNDER HOUSE	(Figure 77)

     Watkin's & Hill (A Descriptive Catalogue, Etc., London, 1836) state, "Mahogany model, called Thunder House, to explain the use of metallic rods as a protection to buildings from the effects of lightning, and also to show the superiority of pointed over rounded surfaces as a quiet and slow conductor of electricity."
     This house, which stands over eight inches high, has hinged sides and roof and it contains a holder for gunpowder which explodes when an electric charge is transmitted to it through a rod attached to the chimney. Rounded topped rods are more vulnerable to a sudden electric spark than are the pointed rods. The chimney and lightning rod are missing from the house in our collection.
     In 1839, in Paris, this house sold for 30 francs.

TUBES FOR ELECTRICAL DISCHARGE	(Figure 78)

     There were many types of these tubes through which electric sparks could be passed. They were used to show the various effects of an electric spark or current on gases of different sorts. The tallest of these instruments is twenty-four inches high. The tube on the left has carbon points. These tubes could be filled with various gases and they could be partially depleted of air by means of a vacuum pump.

UNIVERSAL DISCHARGER	(Not Illustrated)

     The museum has two dischargers. In one the discharge platform is of wood and in the other it is of glass. Dischargers were common pieces of apparatus in the early laboratory. The quote from an early encyclopedia, "...universal discharger of very extensive use in forming communications between jars or directing the shock through any particular substance." (Vol. VI, 3rd Ed., Encyclopedia Britannica, 1788-97.)

VACUUM PUMP	(Figure 79)

     This simple type of vacuum pump was listed for sale in almost every house catalogue a century and more ago. It probably was the one most commonly found in the early laboratories to illustrate certain principles of natural philosophy. It is one of six vacuum pumps in the Transylvania collection.
     This particular pump has no identifying name of its maker.

VACUUM PUMP by CHEVALIER	(Figure 80)

     A pump notable not only for its size and weight but for the fact that it was the first "continuous movement" pump. It was made by the famous instrument maker, Charles Chevalier. Extensive notes came with this pump. They are concerned with its operation, cleaning, etc. Chevalier made several styles of continuous motion pumps. One was made with a single fly wheel instead of the two as in the pump illustrated. A sliding rod receiver is shown in the platform of this pump.
     The pump, and the apparatus which were purchased for use with it, were listed by Dr. Fall as costing $1070.00.

VACUUM PUMP by DELEUIL	(Figure 81)

     Mounted on its own table, which has a drawer for spare parts, this machine was dismantled by students in an effort to clean it. They were unable to reassemble the parts and now some of them (one glass cylinder, for example) are missing. This pump was purchased by Drs. Peter and Bush from Deleuil of Paris for 400 francs in 1839.
     The earliest Deleuil catalogue we have seen was one issued in 1865. But this catalogue states that the Deleuil firm was established in 1820. It also shows that Deleuil won the Médaille d'argent" in an exposition held the same year (1839) in which Dr. Peter bought extensively from the firm. In 1851, at the time of the Great Exhibition of London, Deleuil had both a Paris and a London address.

VACUUM PUMP from PIXII	(Figure 82)

     This is the oldest pump we have. It probably was bought by Dr. Caldwell in Paris in 1821 from Pixii. In 1821 the head of this well known firm was officially listed as "neveu et successeur de Dumotiez." Note that this pump and the one shown in the Figure 81 are operated by an up and down motion of a two handed handle pivoted at the center. This Pixii Air Pump is illustrated by Robert Hare (Compendium of the Course in Chemical Instruction, etc., Philadelphia, 1836). It is spoken of in this text as "a very fine instrument of large size."

VOLTA'S PILE	(Figure 83)

     A device to produce electricity by chemical action, this is a type of wet-cell battery. "Allessandro Volta (1745-1827) was a native of Como, where he was Professor of Physics before he was thirty years old." (A. Wolf. A History of Science, Technology and Philosophy in the 18th century, 1952.)
     This was one of the earliest means employed to produce "voltaic" electricity. "The primary battery was constructed by Volta in 1799. The voltaic pile was made by piling a series of pairs of copper and zinc disks one above the other and separating each pair from the one above by a piece of cloth moistened in a solution of common salt." (Encyclopœdia Brittannica 11th Ed.)

WEDGEWOOD'S PYROMETER	(Figure 84)

     A thermometer designed to measure the temperatures of furnaces from about 1000 to 3000° F. This is, of course, above the range of mercurial thermometers.
     In use this pyrometer depends upon the degree of shrinkage of a small cylinder of pottery clay in the presence of heat. The temperature is determined by noting the place on the scaled trough of the thermometer where the cylinder of clay will wedge after having been subjected to the heat of the furnace.
     A good account of this instrument is given by G. Gregory (A Dictionary of Arts & Sciences, Phila., 1816).
     The pyrometer was brought for thirty francs from Pixii, Paris, in 1839.

ZAMBONI'S APPARATUS	(Figure 85)

     Probably the instrument which Dr. Peter purchased of Deleuil in Paris in 1839 for 60 francs. Zamboni invented a dry voltaic pile (or battery) in 1812. He constructed it of discs of paper rubbed over on one side with peroxide of manganese and coated on the other side with thin tin or silver leaf (Brande and Cox, A Dictionary of Science, Literature and Art, 3 vols. Rev. 1875). The resulting battery does not generate a shock but does generate a small current. D. Lardner (Handbook of Natural Philosophy, Phila., 1853) in discussing dry piles makes the following statement, "In such a pile, neither evaporation nor chemical action taking place, the elements could suffer no change; and the quantity and intensity of the electricity evolved would be absolutely uniform and invariable, and its action would be perpetual."
     The battery base of the apparatus shown is slightly more than seven inches on the side and it contains four sections of the pile with each section about five inches long. The pile, in cross sections, is roughly the diameter of a quarter of a dollar. Above the base a horizontal wire is suspended by a very fine filament. This wire has a small knob at one end and a flattened disc at the other. The disc moves slowly from one pole to the other. This motion has not ceased in the twenty-seven years we have seen the apparatus and probably not for the one hundred and twenty years since its purchase.
     The following items are a few of several for which no data leading to their identification have been found. Very likely as additional exhibit space becomes available and as time is found to clean and identify other instruments, a supplement to this catalogue will be forthcoming. Many pieces of apparatus which were well known to the teachers of science a century ago are not common today. It is either through the chance finding of an illustration in an early textbook, dictionary, or catalogue, or through many hours of searching that some items are identified. A very obvious instrument like Wedgewood's Pyrometer (Figure 84) remained an unknown for some time until it was found in G. Gregory's Dictionary. Zamboni's Apparatus (Figure 85) was identified by name during the past year even though it had occupied a prominent place in the Physics laboratory for almost fifty years. It was so well known, in fact, that it had been dubbed the "perpetual motion machine" by several generations of students. But without dismantling the contents of the heavy base it was difficult to determine the motive force behind the swinging pendulum. Undoubtedly easy identifications can be made of the following few instruments. They are described briefly and illustrated with this aim in view.

     Figure 86 shows a velvet lined mahogany box which is 10-3/4 x 7-1/4 x 2-3/4 inches in size. In the box are found twelve wooden sliders. Each slider has four brass inserts. In the center of each insert is either a pattern of neatly arranged perforations of a steel grating or screen. These sliders are made to pass through the base of a viewing disc (see upper slider in illustration) which, in turn, has rectangular steel grating. This apparatus certainly is designed to illustrate some principle of light.

     Figure 87 represents a small (9 5/8 x 5 x 4 inches) well made box which is divided into eight compartments. In each velvet lined compartment there is a small belljar or receiver. These receivers are not all precisely of the same shape. Their brass tops appear to be made to fit into some receptacle. They have no obvious musical tones when struck.

     Figure 88 shows a well-made footed glass container which has a glass tube extending downward from the brass top. This instrument may be a platinum wire lamp into which someone has put a glass tube in place of the original wick. The screw top might show the spiral platinum wire if it could be removed easily.

     The two items in Figure 89 do not necessarily belong together except that they are obviously made of the same kind of brass and have the same general appearance. Frequently the "qualities" of the brass help in assembling the scattered parts of an instrument. These brass "vases" ("urns") are alike in shape, have open bottoms, one (to the right) has an electric contact shaped like a spout at the side, while the other has an insulated contact at the top. As is true of much of the brass in the collection, these instruments, in some past time, have been coated with a heavy layer of shellac.

     Figure 90 represents a brass cylinder open at both ends. A well made felt covered plunger just fits into the cylinder and can slide all the way through if allowed to do so.

     Several of our most elegant instruments and machines were made by Charles Chevalier of Paris and London. The particular apparatus in Figure 91 has been stamped with Chevalier's name and bears the additional notation "Deux Médailles D'or en 1834" and his Paris address.
     The egg-shaped forms on top of the horizontal platform are made in one piece, each has an insulated electrical contact knob extending from its side, and each is inserted in an opening in the platform. These brass forms can be removed and replaced only in the positions shown, but after having been inserted in the above positions (with the contacts pointing outwardly) they can be rotated freely. The mahogany base is stabilized, as was commonly done in such stands, by means of a heavy lead ring.