Brewster, 1538, D. A Treatise on the Microscope; forming the article, under that head, in the 7th edition of the Encyclopedia Britannica. By Sir David Brewster. Edinburg, 1837.

Carr, 1349, D. A Synopsis of Practical Philosophy, Alphabetically
arranged: containing a great variety of Theorems, For-
mulæ, and Tables in various Branches of Mathematics and
Natural Philosophy; to which are subjoined small Tables
of Logarithms. By John Carr. London, 1843.

Chambers, 1437, D. Elements of Natural Philosophy, in Three
Parts. By Wm. and Robert Chambers. Edited by D. M.
Reese, M. D. New York, 1849.

Comstock, 1318, D. A System of Natural Philosophy. By J. L.
Comstock. New York, 1843.

1348, D. A Manual of Natural Philosophy, with Reca-
pitulatory Questions on each chapter; and a Dictionary
of Philosophical Terms. By John L. Comstock and Rich-
ard D. Hoblyn. London, 1846.

Cunningham, 1646, D. Thoughts on the Causes of Compass Vari-
ation; and the Motions of Planets, Comets, Whirlwinds,
Hurricanes, and Earthquakes. By Peter Cunningham.
London, 1843.

Davy, 1222, 0. Early Miscellaneous Papers, from 1799 to 1805;
with an Introductory Lecture and outlines of Lectures on
Chemistry, delivered in 1802 and 1804. By Sir Humphrey
Davy. (Being vol. 2 of his collected works, by his Brother.)
London, 1839.

1222, O. Bakerian Lectures and Miscellaneous Papers,
from 1806 to 1815. By Sir H. Davy. (Being vol. 5 of
his collected works, by his Brother.) London, 1840.
1222, O. Miscellaneous Papers and Researches, especially
on the Safety Lamp and Flame, and on the Protection of
the Copper Sheathing of Ships, from 1815 to 1828. By Sir
H. Davy. (Being 6th vol. of his collected works, by his
Brother.) London, 1840.

1222, O. Discourses delivered before the Royal Society. Elements of Agricultural Chemistry. Miscellaneous Lectures, and Extracts from Lectures. By Sir H. Davy. 2 vols.

(Being vols. 7th and 8th of his collected works, by his Brother.) London, 1840.

De Morgan, 1294, D. An Essay on Probabilities, and on their application to Life Contingencies and Insurance Offices.

By Augustus De Morgan. (Lardner's Cabinet Cyclopedia.)
London, 1838.

Fales, 1416, O. Horologiographia.-The Art of Dialling: Teaching an easie and perfect way to make all kinds of Dials vpon any plaine plat howsoeuer placed. With the drawing of the twelue Signes, and houres vnequall in them all. Whereunto is annexed, the making and vse of other Dials and Instruments, whereby the hour of the day and night is knowne: of speciall vse and delight not only for Students of the Arts Mathematicall, but also for diueres Artificers, Architects, Surueyours of Buildings, free-Masons and others. By Thomas Fales. At London, 1627.

Farrar, 1567, O. An Experimental Treatise on Optics: comprehending the leading Principles of the Science, and an Explanation of the more important and curious Optical Instruments and Optical Phenomena. By John Farrar. Cambridge, 1826.

Ferguson, 1346, O. Lectures on Select Subjects in Mechanics, Hydrostatics, Pneumatics, Optics, and Astronomy. By James Ferguson. London, 1843.

Gales, 1345, D. Elements of Natural Philosophy; designed for the Use of Schools and Academies. By Leonard D. Gales. New York, 1843.

Graham, 1574, Q. Observations of the Magnetic Dip, made at several positions, chiefly on the South-Western and NorthEastern Frontiers of the United States; and of the Magnetic Declination at two positions on the River Sabine, in 1840. By Major James D. Graham, U. S. Topographical Engineers.

Gregorio, 1416, O. Exercitatio Geometrica de dimensione Figvrarvm sive specimen Methodi Generalis Dimetiendi Quasvis Figuras Auctore Davide Gregorio. Edinbvrgi, 1684. Harris, 1590, O. Rudimentary Electricity: Being a concise exposition of the general principles of Electrical Science, and

the purposes to which it has been applied. By Sir W. Snow Harris. London, 1848.

Hooper, 1388, O. Rational Recreations; in which the Principles of Numbers and Natural Philosophy are clearly and copiously Elucidated by a series of easy, entertaining, and interesting Experiments. By W. Hooper. 4 vols. London, 1783.

Huggeus, 1416, 0. Traite de la Lvmiere oú sont expliquées les causes de ce qui luy arrive dans la Reflexion & dans la Refraction. Et particulierement dans l'etrange Refraction dv cristal d'Islande. Par C. H. D. Z. Avec un Discours de la Cause de la Pesantevr. A. Leide, 1690.

Jackson, 1403, O. An Elementary Treatise on Optics. By I. W. Jackson. New York, 1848.

Jamieson, 1364, O. Mechanics of Fluids, for Practical Men; comprising Hydrostatics, descriptive and constructive. By Alexander Jamieson. London, 1837.

Jones, 1410, D. Conversations on Natural Philosophy; in which the elements of that Science are familiarly explained; with corrections, improvements, &c. By Thomas P. Jones. Philadelphia, 1846.

Kyan, 1481, 0. On the Elements of Light, and their Identity with those of Matter, radiant and fixed. By John Howard Kyan. London, 1838.

Levering & Bond. 1573, Q. An Account of the Magnetic Observations made at the Observatory of Harvard University, Cambridge. By Joseph Levering and W. Cranch Bond. Mc Gauley, 1347, O. Lectures on Natural Philosophy. By the Rev. James William McGauley. Dublin, 1811.

Metcalfe, 1344, O. Caloric: Its Mechanical, Chemical, and Vital Agencies in the Phenomena of Nature. By Samuel L. Metcalfe. 2 vols. London, 1843.

1363, O. A New Theory of Terrestrial Magnetism. By Samuel L. Metcalfe. New York, 1833.

Miller, 1486, O. The Elements of Hydrostatics and Hydrodynamics. By W. H. Miller. Cambridge, 1831.

Molyneux, 1416, O. Sciothericum Telescopicum; or, a new contrivance of adapting a Telescope to an Horizontal Dial for

observing the moment of time by day or night. Useful in all Astronomical Observations, and for Regulating and Adjusting curious Pendulum-Watches and other Timekeepers; with proper Tables requisite thereto. By William Molyneux. Dvblin, 1686.

Monge, 1664, D. An Elementary Treatise on Statics. By Gaspard Monge. With a Biographical Notice of the Author; translated from the French, by Woods Baker. Philadelphia, 1851. Müller, 1236, O. Principles of Physics and Meteorology. By J. Müller. Philadelphia, 1848.

Niogret, 1325, D. D'Electricité et de Galvanisme a l'usage de la Jeunesse. Traduit de l'Anglaise de Joyce. Par Eugéne

Niogret. Paris, 1842.

Olmsted, 1320, O. A Compendium of Natural Philosophy. By Denison Olmsted. New Haven, 1833.

Parker, 1402, D. A School Compendium of Natural and Experimental Philosophy; with a Description of the Steam and Locomotive Engines. By Richard Green Parker. New York, 1848.

Pasley, 1487, O. A Theory of Natural Philosophy, on Mechanical Principles, divested of all immaterial Chymical Properties; showing, for the first time, the Physical Cause of Continuous Motion. By T. H. Pasley. London, 1836. Peschel, 1592, D. Elements of Physics. By C. F. Peschel. Translated from the German, with Notes, by C. E. West. Vols.

2 and 3. London, 1846.

Phelps, 1350, D. Familiar Lectures on Natural Philosophy, for the Use of Schools. By Mrs. A. H. Lincoln Phelps. New York, 1837.

Priestly, 1342, O. Experiments and Observations on different kinds of Air; and Experiments and Observations on various Branches of Natural Philosophy. By Joseph Priestly. 6 vols. London, 1771 to 1786.

Reid, 1362, D. Natural Philosophy: Adapted to Self-instruction, and the Use of Schools. Book first, Pneumatics: containing an Analysis of the Mechanical Properties of Aerial Fluids. By Hugo Reid. Edinburgh, 1841.

Robertson, 1521, O. Mémoires Récréatifs Scientifiques et Anecdotiques du Physicien, Aéronaute. Par E. G. Robertson.

2 tomes. Paris, 1831, 1833.

Sare, 1416, O. The Julian and Gregorian Year: or, the Difference Betwixt the Old and New-Stile. Showing, that the Reformed Churches should not Alter their old stile, but that the Romanists should Return to It. London: Printed for Richard Sare.

1700.

Storrow, 1565, D. A Treatise on Water Works for Conveying and Distributing Supplies of Water; with Tables and Examples. By Charles S. Storrow. Boston, 1835.

Webster, 1351, D. The Elements of Physics. By Thomas Webster. London, 1837.

NAVAL AND COMMERCIAL.

Brady, 1623, 0. The Kedge Anchor; or Young Sailor's Assistant. By William Brady. New York, 1850.

Campaignac, 1643, Q. De l'Estat Actuel de la Navigation par la Vapeur et des Améliorations dont les Navires et appareils a Vapeur Marins sont susceptibles; suivi de notes explicatives, Tableux, Projets, &c. Ouvrage publié sous les auspices du Ministre de la Marine. Par A. Campaignac. Paris, 1842.

Daniels, 1644, 0. The Charges on Vessels (British and Foreign) at all the Ports, Sub-Ports, and Creeks of Great Britain. and Ireland, and Islands thereof; and other Information for the Use of the Shipping Interest in general. By James Brady. Aberdeen, 1843.

Paris, 1217, Q. Administration des Douanes: Tableau Général du Commerce de la France avec ses Colonies et les Puissances étrangères, pendent l'annee. 1834.