Essays on the Microscope / Containing a Practical Description of the Most Improved Microscopes, a General History of Insects, etc., etc.

by George Adams

OPTICAL INSTRUMENTS.
	£.	s.	d.
Best double-jointed standard gold spectacles, with pebbles, and fish-skin gold-mounted case	16	16	0
Ditto single-jointed, with ditto case	10	10	0
Best double-jointed silver ditto, with pebbles	1	16	0
Ditto, ditto, with glasses	1	1	0
Best single-jointed, with pebbles	1	8	0
Ditto, with glasses	0	13	0
Best double-jointed steel ditto, with glasses	0	9	0
An improved sort of ditto for ladies	0	10	6
Second best double-jointed steel spectacles, with spring case	0	7	6
Common ditto	0	4	6
Best single-jointed steel spectacles	0	4	6
Second best ditto	0	2	6
Common ditto	0	1	6
Tortoishell spectacles, silver-jointed, with pointed, and other shaped sides, peculiar for theirlightness and uninterruption of dressed hair, in morocco leather cases	0	10	6
Ditto, double-jointed frames	0	15	0
Spectacles for eyes that have been couched	0	7	6
Ditto with green glasses for very weak and inflamed eyes, according to the frames, from 6s. to	1	1	0
Ditto for the same purpose, with new contrived portable shades to screen the eyes from candle, or other light	0	15	0
Nose spectacles in silver	0	7	6
Ditto in tortoishell and silver.	0	4	0
Ditto in horn and steel	0	1	6
Spectacle cases in very great variety, from 2d. each to	10	10	0
Concave glasses for short-sighted persons, in horn cases	0	1	6
Ditto in tortoishell, pearl, silver, &c. from 2s. 6d. to	2	2	0
Ditto in new-contrived frames for gentlemen when shooting	0	16	0
Reading and burning glasses, in various mountings, from 1s. to	1	16	0
Convex glasses for watch-makers, engravers, &c. from 1s. to	0	10	6
Gogglers, to guard the eyes from the dust or wind	0	3	0
New green-light shades for the eyes	0	6	6
Opera glasses, in great variety of mountings, from 4s. 6d. to	2	12	6
Ditto, on an improved construction of glasses, plain mounting	1	1	0
Refracting Telescopes of various lengths, from 6s. to	1	16	0
Ditto to use at sea by night, from 1l. 11s. 6d. to	2	12	6
Achromatic stick telescopes of various lengths from 18s. to	4	0	0
The new-improved ditto, with three sliding brass tubes, by which an instantaneous view of the object isobtained, and shuts up very short for the pocket, of one foot in length, in a case	1	11	6
Second best two-drawers, ditto	1	1	0
Twenty inch best three-drawers, ditto	2	12	6
Ditto second best two-drawers	1	10	0
Two feet best three-drawers, ditto	4	4	0
Ditto second best, ditto	3	3	0
Three feet, best four-drawer ditto	6	6	0
Second best ditto	4	4	0
The preceding telescopes, fitted up elegantly with silver or plated tubes, from 2l. 2s. to	21	0	0
Astronomical eye-pieces and portable brass stands for the above, from 10s. 6d. to	2	12	6
The new-improved 21⁄2 feet achromatic refractor, on a brass stand, mahogany tube,with two sets of eye-glasses, one magnifying about forty times for terrestrial objects, and the other about seventy-five times forastronomical purposes, packed in a mahogany box	9	9	0
Ditto, ditto, the tube all brass, with three eye-pieces	11	1	6
The 31⁄2 feet ditto, ditto, mahogany tube	17	6	6
Ditto, ditto, brass tube	19	8	6
Ditto all in brass, with rack-work motions, &c.	24	3	0
Achromatic perspective glasses for the pocket, in brass, &c. tubes, with a change of eye-glasses,from 12s. to	3	3	0
New-improved ditto, answering the purpose of an opera-glass, with a compass, and helioscope for viewing the sun,from 1l. 3s. to	2	2	0
New-improved achromatic pocket telescope, which, by a small apparatus within its tubes, is readily converted intoa compound microscope	3	13	6
An improved portable seven-inch achromatic telescope in brass, with a stand that packs up into the tube of thetelescope, adapted for astronomical uses	3	13	6
Reflecting Telescopes, fitted up either upon the Gregorian, Newtonian,or Herschelian principles, with improved wood, or metal stands, and other apparatus for making celestial observations in the mostcommodious and accurate manner—The general prices are as follow:
— Fifteen feet in length, the large metal fifteen inches in diameter, from 250l. to	500	0	0
— Twelve feet in length, fourteen inch metal	200	0	0
— Ten feet in length, twelve inch metal	150	0	0
— Eight feet in length, eleven inch metal	140	0	0
— Six feet in length, nine inch metal	100	0	0
— Four feet long, in brass tubes, with portable brass or mahogany framed stands, from 40l. to	100	0	0
Those reflectors that are constructed upon the principles of NewtonorHerschel are about twice the above lengths in the tubes. The reflectors uponthe usual Gregorian construction are made with the vertical motion upon a new principle, so as to render them more firm and steady whilein use, than any reflectors mounted in the old manner.
A four feet seven inch aperture Gregorian reflector, with the vertical motion upon a new invented principle, aswell as apparatus to render the tube more steady in observation; according to the additional apparatus of small speculums, eye-pieces,micrometers, &c. from 70l. to	100	0	0
Three feet long, mounted on a brass stand, common mounting	23	2	0
Ditto with rack work motions, improved mounting, and metals	36	15	0
Two feet long, without rack-work, and with four magnifying powers, improved, 13l. 13s. to	14	14	0
Ditto improved, with rack-work motions	22	1	0
Eighteen inch on a plain stand	8	8	0
Twelve inch ditto	5	5	0
Telescopes of both the above kinds fitted up. with equatorial, &c. motions, micrometers, adjusting,compensating, &c. apparatus, for the most accurate astronomical purposes.
Common Microscopes, from 2s. 6d. to	1	1	0
Wilson’s single pocket microscopes, from 18s. to	2	12	6
Compound microscopes improved, from 2l. 12s. 6d. to	5	5	0
New improved universal ditto	6	6	0
Ditto with the most complete apparatus	10	10	0
Solar microscopes in brass, improved, from 4l. 14s. 6d. to	6	6	0
The new opake and transparent solar microscopes, with improved apparatus, from 10l. 10s. to	16	16	0
Ditto of a larger size, with additional megalascopic apparatus, from 14l. 14s. to	19	19	0
Ditto, and best compound ditto, packed together in one mahogany box	21	0	0
The Lucernal Microscope, as improved by W. Jones,exhibiting images of opake and transparent objects by night or day, in a manner singularly pleasing, brilliant and distinct, withupwards of 100 objects, proper apparatus, patent lamp, &c.	16	16	0
Ditto combined with a solar, compound, &c. apparatus, forming the most perfect collection of microscopicalapparatus	35	14	0
A portable optical apparatus, consisting of a scioptic ball and socket, a solar microscope, Wilson’smicroscope, a pocket compound microscope, a pocket telescope, and solar telescope, in mahogany and brass	3	13	6
Pocket microscopes for opake objects, from 16s. to	2	12	6
Botannic microscopes for flowers, &c. from 5s. to	1	11	6
A new universal pocket ditto, adapted to all sorts of objects	1	6	0
Cloth microscopes, from 2s. 6d. to	0	10	6
Magic lanthorns, from 1l. 4s. to	1	8	0
Sliders for ditto in great variety of subjects, each	0	3	6
A new set of moveable painted sliders, shewing the fundamental principles of astronomy, with the real andapparent motions and positions of the planets, stars, &c. &c. accompanied by aproper improved lanthorn, complete	13	13	0
Small magic lanthorns, with twelve sliders complete, at 7s. 6d. 10s. 6d. 12s. and	1	0	0
Ditto with twelve sliders of best English paintings	2	2	0
Optical diagonal machines for viewing prints, from 1l. to	1	11	6
Perspective views in great variety for ditto, each	0	1	6
Scioptic balls and sockets from 10s. 6d. to	1	11	6
An artificial eye in brass, to exemplify the nature of vision	1	11	6
For a description of this instrument, as well as of spectacles, reading-glasses, &c.see the late Mr. G. Adams’s Essay on Vision, 8vo. price 3s. now sold byW. and S. Jones.
Camera obscuras for the pocket, from 9s. to	1	16	0
A new invented folding ditto, very portable	2	2	0
Large ditto, shutting up like a book, or neat portable chest, the objects represented on paper, from 4l. 14s. 6d.to	8	18	6
Concave and convex glass mirrors, in plain black frames, four, five, six, and seven inches diameter, each 9s.12s. 14s. and	0	18	0
Eight inches diameter ditto	1	1	0
Nine inches ditto	1	7	0
Ten inches ditto	1	12	0
Twelve inches ditto	2	5	0
Fifteen inches ditto	3	13	6
Eighteen inches ditto	6	6	0
Twenty-one inches ditto	11	11	0
Twenty-four inches ditto	16	16	0
Concave mirrors, ground cylindrically, possessing several curious properties in the deformation of objects,according to the size, from 1l. 1s. to	5	5	0
Concave metal burning mirrors, superior to the glass ones, from 3l. 13s. 6d. to	21	0	0
Glass prisms, plain, or mounted on stands, from 7s. 6d. to	1	11	6
A curious set of optical models, where the rays of light are represented by silken strings, and illustrating theprinciples of vision, telescopes, prisms, &c. packed in five cases	6	16	6
MATHEMATICAL INSTRUMENTS.
Theodolites of the common construction, and of the best workmanship, from 4l. 4s.to	31	10	0
A portable theodolite, with a telescope, level, and vertical arch	7	7	0
Ditto larger, with parallel plates, &c. divided to two minutes	12	12	0
Ditto with rack-work motions, divisions to a minute	22	1	0
A new-improved theodolite, with two telescopes, and contrivances for every accurate adjustment	36	15	0
A new very portable theodolite, by rack-work, measuring angles with equal accuracy as those of the common largesort, is at the same time applicable for taking altitudes, and is truly adapted for the purpose of levelling	8	8	0
A 4-inch further improved ditto, by which the vertical and horizontal angles are shewn at the same time, withportable staves, &c.	10	10	0
Circumferentors, much used in wood lands, from 2l. 2s. to	4	4	0
An improved ditto, contrived to answer the purposes of a common theodolite, level, altitude instrument,&c.	4	14	6
Surveying crosses or squares, on a staff, from 12s. to	1	11	6
A brass cylindrical ditto, with a staff	0	18	0
Ditto with compass, agate capped needle, &c.	1	11	6
Improved ditto, with rack-work and pinion, and moveable divided limb, making a very portable cross-staff, compassand theodolite in one instrument	2	18	0
Levels of the latest improvements, from 2l. 2s. to	12	12	0
Station staves, with sliding vanes, for levelling	2	12	6
Plane tables, with index, sights, &c. complete, from 3l. 13s. 6d. to	5	5	0
Pentagraphs, by which any person unskilled in drawing may copy plans, surveys, profiles, drawings, &c. in anyproportion to the original, from 1l. 16s. to	6	16	6
Perambulators or measuring wheels, from 61. 6s. to	10	10	0
Gunter’s measuring chain, according to strength, from 5s. to	0	11	0
—— navigation scale, from 2s. to	0	4	0
—— ditto improved by Donn, with book of directions	0	5	0
—— ditto improved by Robertson, with brass adjusting screws, &c. being the completest scale ofthe kind	1	10	0
—— sectors of various lengths, from 2s. to	1	11	6
A new pocket ten inch box sliding rule for solving all sorts of problems in trigonometry, &c. from 2s. 6d.to	0	4	0
Measuring tapes, one, two, three, and four poles, 5s. 7s. 6d. 9s.	0	10	6
Pedeometers for ascertaining distances in walking or riding, of a watch size for the pocket, and also to applyto carriages, from 31. 3s. to	12	12	0
Miner’s compasses, for working in subterraneous grounds, from 10s. 6d. to	1	11	6
Cases of drawing instruments, from 4s. 6d. to	5	5	0
Magazine, or complete collection of every kind of useful drawing instruments, from 5l. 5s. to	35	0	0
A new portable drawing board and seat, the board folds up for the pocket, and the legs of the seat form a walkingstick	0	18	0
Proportional compasses, from 1l. 10s. to	3	3	0
Elliptical compasses of various degrees of perfection and utility, from 16s. to	4	14	6
Spiral and elliptical compasses, from 6s. 6d. to	10	10	0
Triangular compasses, by which three points at once may be transferred, from 13s. to	1	5	0
Hair compasses that take extents to a great accuracy	0	7	6
Beam compasses for dividing large circles, projections, &c. from 1l. 1s. to	10	0	0
Bow compasses for describing very small circles, from 2s. 6d. to	0	12	0
Perspective compasses to take angles, &c. from 1l. 5s. to	2	12	6
Parallel rulers of different constructions, from 2s. to	2	12	6
Protractors for laying down angles, from 2s. to	1	1	0
Ditto, with a nonius and moveable limb	2	2	0
Ditto, ditto, with teeth and pinion	4	10	0
Sets of protracting and plotting scales; instruments for dividing lines or transferring divisions on paper. Aninstrument for describing circles from four to six inches radius, or to the utmostconceivable distance—Gunners callipers—Gunners levels or perpendiculars—Shot gauges—Shell ditto—Gunnersquadrants, with a plummet or level, or adjusting screw, &c. and all other instruments for military purposes.
Hadley’s Quadrants, mahogany, the divisions on wood	1	11	6
Ditto mahogany with ivory arch and nonius, double observation	2	2	0
Ditto, ditto, a brass index, double observation	2	12	6
Ditto, ebony and brass, best glasses, engine divided, &c.	3	0	0
Ebony and brass mounted best sextants, from 4l. 4s. to	8	18	6
Metal ditto, all brass, framed on a principle the least liable to be warped or strained, with adjusting screws,telescopes, and other auxiliary apparatus, the most proper for taking distances accurately, to determine the longitude at sea,&c.	12	12	0
Ditto, second best	8	8	0
A new small 3-inch pocket box sextant to take angles to a minute, from 2l. 2s. to	3	3	0
Artificial horizons, by parallel glasses and quicksilver, to take double altitudes by	1	16	0
Gunter’s quadrant, from 4s. to	1	1	0
Azimuth compasses of different constructions, from 5l. 5s. to	12	12	0
Pocket compasses from 2s. 6d. to	5	5	0
Horizontal sun-dials, in brass, made for any latitude, of four, five, or six inches diameter, divided into fiveminutes of time, each at 6s. 9s. and	0	12	0
Ditto seven inches	0	16	0
Ditto eight inches, into two minutes	1	4	0
Ditto ten inches, ditto	1	16	0
Ditto twelve inches, ditto	2	10	0
Ditto, fifteen inches, into every minute, thirty-two points of the compass, &c.	4	14	6
Ditto eighteen inches, ditto, ditto, with equation table, &c.	8	8	0
Ditto 2 feet diameter, ditto, ditto	15	15	0
A new universal ditto and equatorial, making a very portable angular instrument, from 8l. 8s. to	31	10	0
Universal ring dials, from 7s. 6d. to	10	10	0
For a general description and representation of the instruments used in surveying,levelling, and other branches of practical geometry, see the late Mr. G. Adams’s Geometrical andGraphical Essays, an improved edition by W. Jones, in two vols, 8vo. 1797, with thirty-five foliocopper-plates. Price 14s.
ASTRONOMICAL, &c. INSTRUMENTS.
A portable Transit Instrument, with a cast iron stand, to ascertain the rate ofchronometers, the longitude, &c. the axis is twelve inches in length, and the telescope about twenty inches, packed in a case	12	12	0
Ditto, with a brass framed stand, and other additions	20	0	0
Transit instruments of larger dimensions made to order.
The new Circular Instruments and Equatorials, from 63l.to	180	0	0
Planetariums, shewing the phænomena of the Ptolemaic andCopernican systems, from 7l. 7s. to	50	0	0
Manual orreries of the common construction from 2l. 12s. 6d. to	6	6	0
Jones’s (Wm.) new portable orrery, the tellurian part	1	1	0
Ditto, the planetarium part	1	1	0
Tellurian and planetarium together, making the New Portable Orrery, packed in a neat mahogany box,according to the sizes, from 2l. 12s. 6d. to	5	5	0
An orrery shewing the motions of Mercury, Venus, the Earth and Moon, by wheel-work, the Earth is a11⁄2 inch globe, packed in a box	4	4	0
Other planetariums and orreries in great variety, the motions by wheel-work, exemplifying all the motions andphænomena of all the planets, the Georgium Sidus included, from 40l. to	1000	0	0
Cometariums, for exemplifying the motion of comets, from 1l. 11s. 6d. to	5	5	0
Senex’s globes improved, twenty-eight inches diameter, mahogany frames, from 25l. to	50	0	0
Twelve inch ditto, improved by Ferguson, with all the new discoveries of Capt. Cooke, &c. with the new hourcircles, which supersede all the intended advantages of cumbersome wires, and other appendages, in other globes, mounted in neat mahoganyclaw-feet frames	5	5	0
Ditto, in common coloured wood frames	3	3	0
Additional price of a compass, and fitting to both globes	0	5	0
A pair of red leather covers for the globes	0	9	6
Globes, nine inches diameter, with the new discoveries	2	2	0
Ditto, three inches ditto, in claw-feet, mahogany frames	1	10	0
Ditto, three inches single, one in a case for the pocket	0	9	0
Geographical planispheres, to solve problems, mounted as a hand fire-screen	0	7	6
A brass armillary sphere, three inches diameter	3	3	0
A six inch ditto	6	6	0
A nine inch ditto	9	9	0
A twelve inch ditto	12	12	0
Larger ditto, with planetarium, from 21l. to	105	0	0
For a general description of orreries and other astronomical instruments, see the lateMr. G. Adams’s Astronomical Essays, 8vo. with sixteen plates; price 10s. 6d. now sold byW. and S. Jones.
PHILOSOPHICAL, &c. INSTRUMENTS.
A single-barrel Air Pump, with receiver	2	12	6
Improved ditto, exhausting more accurately	5	15	6
A small double-barrel air pump, with gage plate	5	5	0
A middle size ditto	6	16	6
A large size table ditto	10	10	0
Air pumps of the largest sort, exhausting more accurately, from the constructions of the different inventors.
Condensing engines, from 5l. 5s. to	21	0	0
Papin’s digester improved, on a stand	5	15	6
The principal Apparatus for the Air Pump asfollow:
Guinea and feather apparatus, demonstrating the resistance of the air, with one, two, or three falls, from 18s.to	1	11	6
A set of wind-mills, for the same demonstration	1	11	6
The brass hemispheres, shewing the air’s external pressure, from 14s. to	1	10	0
A bell, proving that there is no sound without air	0	10	6
Improved constructions of this bell, from 1l. 1s. to	3	3	0
Lead weights, with bladder, &c. proving the air’s elasticity	0	17	0
The double transferrer, that transfers a vacuum from one receiver to another, by turning stop-cocks only	3	0	0
A model of a water-pump, exemplifying the nature of pumps, and proving the absurdity of what is called suction	1	4	0
A single transferrer, plate and pipe, for a fountain	0	18	0
A copper air-pipe for experiments on infected air	0	17	0
A flat plate, collar of leathers, with sliding wire, for placing on receivers	0	12	0
An apparatus for firing gun-powder in vacuo	0	18	0
A copper bottle, beam and stand, for accurately weighing of air	2	12	6
A glass vessel for making a fountain in vacuo	0	5	6
Ditto on a larger, and different construction	0	16	0
A glass with a bladder, shewing the action of the lungs	0	6	0
Ditto mounted with the figure of a Bacchus	1	10	0
A balance beam and stand	0	7	0
A filtering cup shewing the porosity of vegetables	0	5	0
A plate and piece of wood for the same purpose	0	4	6
An apparatus for striking flint and steel in vacuo	0	18	0
The Torricellian experiment	0	18	0
Fruit stand	0	3	6
Candlestick	0	3	6
Syringe with lead weight	0	10	6
Six breaking squares, cage and cap	0	7	6
Glass bubble and stand	0	3	0
Hand and bladder glasses	0	3	6
With a great variety of receivers, and other apparatus, described by various authors.
Exhausting and condensing syringes, from 10s. 6d. to	1	11	6
Exhausting syringes, with sets of cupping glasses, breast glasses, and scarificator, complete	4	14	6
Air fountains of copper, with various jets, from 3l. 13s. 6d. to	7	7	0
Electrical Machines, with conductors and jars, from 2l. 12s. 6d. to	10	10	0
New and much improved ditto, from 3l. 13s. 6d. to	42	0	0
Electrical machines and complete apparatus, for medical purposes, packed in boxes, the cylinder from seven toten inches diameter, from 6l. 6s. to	12	12	0
An electrical machine, with apparatus for philosophical experiments and medical uses, packed in a box, thecylinder about eight inches diameter	8	18	6
Apparatus for Electrical Machines as follow:
Electrical batteries of combined jars, from 2l. 12s. 6d. to	10	10	0
An universal discharger, with a press	1	8	0
A quadrant electrometer, with divided arch	0	7	6
Jointed dischargers, with glass handles	0	10	6
Plain ditto, ditto	0	5	6
An useful and illustrative apparatus, compounded of the luminous conductor, exhausted flask, two jars, exhaustedsyringe, insulated stand, and wires with balls, &c. complete	3	0	0
Luminous conductors, from 12s. to	1	5	0
Exhausted flasks, called Aurora Borealis	0	6	6
A thunder house, demonstrating the use of conductors	0	6	0
A powder house, for the same purpose	0	16	0
An obelisk or pyramid for ditto	0	10	6
A set of plain bells, three to a set	0	7	6
A new set of musical ditto, containing the gamut	1	10	0
A magic picture for giving shocks	0	7	6
An electrical cannon, to be discharged by inflammable air	0	16	0
Brass pistols for ditto	0	7	6
Spiral tubes, to illuminate by the spark, from 4s. 6d. to	0	10	6
Luminous names, or words, from 10s. 6d. to	1	11	6
Spotted jars, from 6s. to	0	10	6
A double jar for explaining the Franklinian theory	0	15	0
Copper plates and stands for dancing images	0	9	0
An electrical tin fire house	0	10	6
An electrical shooter and mark	0	5	0
A mahogany stand for eggs	0	4	6
A small head with hair	0	7	6
An artificial spider	0	1	6
An electrical swan	0	2	0
An electrical star	0	1	6
Balls of wood, bone, &c. each from 6d. to	0	2	6
A curious collection of working models, to be set in motion by the electrical fluid, consisting of a corn milland a three-barrelled water-pump, worked by one crank only: an orrery, shewing the diurnal motion of the earth, age and phases of themoon, &c. and astronomical clock, shewing the aspects of the sun and moon, age, phases, &c. all delicately made of card paper,cork, and wire only, packed in a deal case	2	12	6
Kinnersley’s electrical air thermometer	1	1	0
Cavallo’s atmospherical electrometer	0	12	0
Ditto, as improved by Saussure	1	1	0
Bennet’s gold leaf electrometer	0	18	0
Nicholson’s spinning doubler.	1	10	0
An electrophorus, from 10s. 6d. to	3	3	0
Conductors for the preservation of ships, houses, &c. from lightning, from 3l. 3s. to	5	5	0
The medical Apparatus consists of,
Jars with electrometers, from 12s. to	1	1	0
A new medical ditto, for communicating shocks in the most convenient and qualified manner	0	7	6
A pair of directors, glass handles, wood points, &c.	0	7	6
An electrometer to apply to the conductor	0	6	6
Electrical insulated stools and chairs, from 9s. to	5	5	0
A new perpetual inflammable air lamp, lighted by the electrophorus, a curious and useful apparatus	4	4	0
A variety of other apparatus, too numerous to be inserted here, which as well as the machines,are mounted from the most approved, eligible methods, so as to render them in action both powerful and permanent.
For a complete description of electrical apparatus, see the late Mr. G.Adams’s Essay on Electricity, 8vo. six plates; price 6s. now sold by W. andS. Jones.
Barometers plain mounted from 1l. 11s. 6d. to	2	12	6
Thermometers for all the various purposes, from 9s. to	3	3	0
Six’s new thermometers, for shewing the extremes of heat and cold, in the absence of the observer, from 1l.11s. 6d. to	2	12	6
An hygrometer, shewing the moisture and dryness of the air	0	10	6
Barometers, thermometers, and hygrometers, all in one neat mahogany frame, from 4l. 4s. to	6	6	0
Barometers for measuring the heights of mountains from 7s. to	10	10	0
Marine barometers, diagonal, wheel, and statical ditto.
New hygrometers constructed by De Luc, &c. from 2l. 2s. to	3	3	0
A rain gauge, with float and tin vessel	0	18	0
Wind gages, of the constructions of Dr. Lind, &c.	0	16	0
Hydrometers for discovering the strength and proportion of compound in spirituous liquors, from 1l. 7s. to	3	3	0
Hydrostatic balances, from 1l. 1s. to	9	9	0
An apparatus for hydrostatical experiments, from 3l. 13s. 6d. to	21	0	0
Artificial magnets in bars, and sets of bars, from 2s. 6d. to	6	6	0
Ditto, in the shape of a horse-shoe, the strongest form, from 1s. 6d. to	1	1	0
Ditto, combined to any number, from 12s. to	21	0	0
A box of magnetical apparatus illustrating a variety of curious and entertaining properties in magnetism, from5l. 5s. to	7	7	0
Dipping needles, variation, and other compasses, in great variety.
Pyrometers, shewing the expansion of metals, from 3l. 3s. to	10	10	0
The mechanical powers, for illustrating and demonstrating the laws of motion, gravity, &c. a set neatly madein brass, consisting of the balance, the pullies, the different kinds of levers, the inclined plane, the wheel and axle, the screw, acompound engine, a compound lever, a double cone to move up an inclined plane, friction wheels, weights, wedges, &c. complete	25	4	0
The same occasionally made on a more enlarged plan, for a large auditory.
Ditto, with many parts of the apparatus made of mahogany, and the whole set packed in a neat mahogany box	14	14	0
Separate sets of pullies, variously constructed and combined.
A small carriage with inclined plane, and wheels of different sizes, &c. experimentally proving thefriction, resistance, &c. of all sorts of wheel carriages	7	7	0
Ferguson’s compound engine, in which all the simplemechanical powers work together	4	4	0
A whirling table, for explaining and demonstrating the laws of the planet’s motion, the demonstrationsof the doctrine of the tides, and other properties of gravity and centrifugal force, from 7l. 7s. to	16	16	0
Atwood’s elegant and accurate apparatus for demonstrating the laws of accelerated and retarded motion, andother interesting particulars	25	4	0
Several small mahogany models for explaining the center of gravity, the line of direction, &c.	2	2	0
FOR PHILOSOPHICAL CHEMISTRY.
Glass bottles with bent necks, from 4s. to	0	10	6
A glass machine for impregnating water with fixed air, and apparatus	2	12	6
Glass eudiometer tubes, for ascertaining the salubrity of airs, &c.	0	10	6
Ditto as improved by Abbe Fontana, &c.	2	4	0
Gazometers by Priestley, Lavoisier, &c. from 1l. 1s. to	5	5	0
A blow-pipe, with various caps, for fluxing metals, &c.	0	7	6
Ditto, with silver spoon, megalascope, &c.	1	1	0
Ditto, ditto, with a variety of other necessary apparatus, packed in a fish-skin case, forming Cronstedt’scomplete pocket laboratory, improved by Magellan	2	12	6
Magellan’s new portable lamp furnace, with the blow-pipe, small glass retorts, &c. &c. for chemicalas well as mineralogical operations	4	14	6
Ditto, with the double bellows to apply to the blow-pipe	7	7	0
Double bellows, with deal table, and appendages, for glass blowing	2	12	6
A wooden tub for water, and another for quick-silver, with a selection of glass apparatus for performing thelate discovered experiments on air	6	6	0
A box, containing all the useful precipitants of Bergman, &c. for analysing waters, and fluxes for theblow-pipe in phials with glass stoppers, with Gottling’s printed description of ditto	4	8	0
A mahogany case containing, in phials, a variety of preparations for young persons to perform amusive andinstructive chemical experiments	3	13	6
Fumigating bellows for destroying insects in gardens, by tobacco, from 1l. 6s. to	1	16	0
Instruments of Recreation and Amusement.
The sensitive fishes, that have the property of swimming to a piece of bread placed at the end of a stick; and,when the other end is presented, of retreating and going back, sensible, as it were, of no substance for them to eat	0	6	6
The sagacious swan, that with a machine makes three kinds ofamusements—1st. the swan will point out the secrets of the cards; 2d. it will point answers to 16 humorous enigmas; and 3d.disclose any particular hour that was thought of, such as going to bed or rising; packed in a case	1	18	0
A box containing four numbers and four letters, the order of which may be discovered, if ever so secretly placed,by means of a curious magic perspective	0	10	0
Ditto with five numbers, no perspective, but another very similar box, made in neat mahogany boxes, and moredifficult to discover the reason of	1	18	0
A curious magic oracle, unfolding answers to any proposed questions secretly taken out of a bag	0	16	0
A magic painter, exhibiting a copy of any one of eight different paintings secretly chosen	0	10	6
A communicative mirror, shewing portraits of any one of four secretly chosen; an elegant and curiousinstrument	2	12	6
A box containing five pieces of different metals, which may any way be secretly placed, and their situation betold by the magical perspective	1	8	0
An optical paradox, containing two perspectives, between which a board may be placed, and the object will beseen through them just as well as if the board was not there	0	7	6
Ditto mounted in mahogany, larger size	1	8	0
An optical deception, containing from six to twelve different paintings, and which are looked down upon througha perspective, and immediately there appears another very different object, without any alteration of the instrument whatsoever, orconcern of the person using it, from 1l. 11s. 6d. to	3	3	0
A diagonal opera glass, that shews persons on one side, when the glass is presented to the object directlybefore you, from 6s. to	0	15	0
A multiplying glass, making one object appear a great number, from 1s. 6d. to	0	10	6
A set of anamorphoses or deformed pictures rectified by a polished cylinder	2	2	0
A mathematical recreation, containing near seventy figures on a card; any one figure being thought of, is readilypointed out by any one using it	0	1	0
The two curious mathematical cubes, one of which is gauged so as to prove it to be larger than the other, yet thelarger one will actually pass through the smaller one, and not in any degree stretch it	1	0	0
The mathematical paradox, a piece of wood of one figure, fits exactly, and passes through a triangular, a square,and a circular hole	0	2	6
A double cone, that apparently rolls upwards up an inclined plane, though actually descending	0	4	6
A magic well, in which may be put four buckets full of different seeds, and fairly mixed together; any particularseed of the above four kinds may be drawn up separately, and, when examined, will be found to beperfectly pure	1	11	6
A mechanical instrument, consisting of a cube and two wooden handles, that supports itself on a point, althoughthe entire form and weight appear evidently all on one side	0	12	0
A cylindrical mirror that produces two or three curious optical effects	1	1	0
A magic or electrical bottle, that is charged by the rubbing of a ribband only, and will give a shock to five orsix persons, with apparatus, in a pocket case	0	10	6
A set of the artificial fireworks imitated, containing a series of brilliant and entertaining scenes of fireworks,cascades of fire, &c. producing altogether a pleasing effect, and not attended with any trouble, noise, or danger, when using; thewhole contained in a neat mahogany box	7	7	0
The magic lanthorn apparatus conjoined with the above	10	10	0
Concave mirrors fitted up in boxes, to magnify prints, to shew various deceptions in an entertaining and pleasingmanner, from 5l. 5s. to	12	0	0
Besides the preceding, a great variety of other articles too numerous to be included in thiscatalogue, as well as any instrumental article made from particular drawings, or as described by the different writers upon mathematics,philosophy, chemistry, &c. &c.
Merchants, shopkeepers, schoolmasters, and others that sell again, are supplied with the bestarticles, and with good allowance.
Letters from the country or abroad, containing orders or previous enquiries, explicitly andpunctuallyattended to.
Les académies, observatoires et ecolesdes pays etrangers ainsi que les négociants,merchands et autres personnes peuvent se procurer toutes sortes d’instruments de la meilleure qualité, tant pour lesmatériaux, que la main d’œuvre, avec la plus grande expédition, et au plus juste prix.
BOOKS published by W. JONES.
A Description and Use of the New Portable Orrery, to which is prefixed a short account of the solar system,including the new planet, the burning mountain in the moon lately discovered by Dr. Herschel, and the probable reasons why the cometdid not appear, as lately expected, with two copper-plates, 4th edition	0	1	6
A Description and Use of the Hadley’s Quadrant, with an account of all the new apparatus added to it,for taking observations accurately, in order to determine the longitude at sea, illustrated by copper-plate figures, 2d edit.	0	1	0
A Description and Use of the Pocket Case of Mathematical Drawing Instruments, illustrated by copper-platefigures	0	0	8
Methods of finding a Meridian Line, to set sun-dials, regulate clocks and watches, &c.	0	0	6
Directions for finding a Meridian Line, on a card	0	0	3
A Concise Explanation of the Barometer, Thermometer, andHygrometer, with rules for predicting changes in the weather, in a small book, 6d. on a pasteboard, varnished	0	1	0
Cowley’s Illustration of Solid Geometry, containing 42 copper-plates of moveablefigures; a work very useful and convenient for teachers and young students of geometry, as the figures, when folded up, form exactly thesolid figures of the Platonic bodies, conic sections, and several portions of Euclid’s Elements, &c. &c. boards	0	18	0
Other BOOKS sold by W. and S. JONES.
QUARTO.
The New Encyclopædia Britannica (printed at Edinburgh) a new edition, quarto, in 18 vols, or 36 parts,now complete, in boards price	18	18	0
This Dictionary of Arts and Sciences is upon a new and enlarged plan, and contains the systems of thedifferent arts and sciences, under the different heads, as well as the explanations of the various detached terms.
Hutton’s (Dr.) Mathematical Dictionary, 2 vols. boards	2	12	0
Nicholson’s Philosophical Journal, four numbers, all that are now published, each 2s. 6d.	0	10	0
The Philosophical Transactions of the Royal Society, containing 11 vols. of the Abridgement; and from thence,the Continuation at large to the present time; the index, with Birch’s and Sprat’s history, 5 vols. all in uniform cleancalf binding and tooled backs, in 58 vols.	60	0	0
Vince’s Treatise on Astronomy, 1st vol. sewed	1	4	0
OCTAVO.
Cavallo’s Treatise on Magnetism, with Supplement	0	8	0
Kelly’s Practical Introduction to Spherics and Nautical Astronomy	0	6	0
Moore’s Practical Navigator, or Seamen’s Daily Assistant	0	6	0
Nicholson’s First Principles of Chemistry, boards	0	7	6
—— Introduction to Natural Philosophy, 2 vols.	0	12	0
Nautical Almanacks, a complete set bound, 28 volumes	5	5	6
Ditto for any year to 1800	0	3	6
Requisite Tables to the above, unbound	0	5	0
Robertson’s Elements of Navigation, new edit. 2 vols.	1	0	0
Wale’s Method of finding the Longitude by Time-keepers, and Description of a Portable Transit Instrument,&c.	0	2	6

FINIS.

---

London, Dec. 1, 1797

W. and S. Jones take this Opportunity of informing the Public that they have purchased the Stock and Copyright of the several Philosophical Essays by the late Mr. George Adams, of Fleet Street, and that they are now sold at their Shop in Holborn. The following are those now in print, and to be had as above.

I. AN ESSAY ON ELECTRICITY, explaining clearly and fuly the principles of that useful Science, describing the various Instruments that have been contrived either to illustrate the Theory, or render the Practice of it entertaining. The different Modes in which the Electrical Fluid may be applied to the human Frame for medical Purposes, are distinctly and clearly pointed out, and the necessary Apparatus explained. To which is now added, A Letter to the Author, from Mr. John Birch, Surgeon, on the Subject of Medical Electricity. Fourth Edition, 8vo. Price 6s. illustrated with six Plates.

II. AN ESSAY ON VISION, briefly explaining the Fabric of the Eye, and the Nature of Vision; intended for the Service of those whose Eyes are weak and impaired, enabling them to form an accurate Idea of the State of their Sight, the Means of preserving it, together with proper Rules for ascertaining when Spectacles are necessary, and how to choose them without injuring the Sight. 8vo. Boards, Price 3s. Second Edition.

III. ASTRONOMICAL AND GEOGRAPHICAL ESSAYS, containing, 1. A full and comprehensive View, on a new Plan, of the general Principles of Astronomy, with a large Account of the Discoveries of Mr. Herschel. 2. the Use of the Celestial and Terrestrial Globes, exemplified in a greater Variety of Problems than are to be found in any other Work: they are arranged under distinct Heads, and interspersed with much curious but relative Information. 3. The Description and Use of small Orreries and Planetaria, &c. 4. An Introduction to Practical Astronomy, by a Set of easy and entertaining Problems. Third Edition, 8vo. Price 10s. 6d. in Boards, illustrated with sixteen Plates.

IV. AN INTRODUCTION TO PRACTICAL ASTRONOMY, or the Use of the Quadrant and Equatorial, being extracted from the preceding Work. Sewed, with two Plates, 2s. 6d.

V. GEOMETRICAL AND GRAPHICAL ESSAYS. This Work contains, 1. A select Set of Geometrical Problems, many of which are new, and to be found in no other Work. 2. The Description and Use of those Mathematical Instruments that are usually put into a Case of Drawing Instruments. Besides these, there are also described several New and Useful Instruments for Geometrical Purposes. 3. A complete and concise System of Surveying, with an Account of some very essential Improvements in that useful Art. To which is added, a Description of the most improved Theodolites, Plane Tables, and other Instruments used in Surveying; and most accurate Methods of adjusting them. 4. The Methods of Levelling, for the Purpose of conveying Water from one Place to another; with a Description of the most improved Spirit Level. 5. A Course of Practical Military Geometry, as taught at Woolwich. 6. A short Essay on Perspective. The Second Edition, corrected, and enlarged with the Descriptions of several Instruments not contained in the former Edition, by W. Jones, Mathematical Instrument Maker; illustrated by thirty-five Copper-plates, in 2 vols. 8vo. Price 14s. in Boards.