A SYNOPSIS

OF THE SCIENTIFIC WRITINGS OF SIR WILLIAM HERSCHEL.

BY EDWARD S. HOLDEN AND CHARLES S. HASTINGS.

I.-INTRODUCTORY NOTE.

The astronomical life of Sir WILLIAM HERSCHEL covered forty-two years. During this period he published no less than sixty-nine different memoirs, which are scattered through the annual volumes of the Philosophical Transactions of the Royal Society of London from 1780 to 1818. Two generations have passed since his death, and we have no readier means of studying his works than in the original volumes of the Transactions, now become rare and costly. Students of astronomy and physics are thus often compelled to know his writings at second-hand from textbooks, and not in the vigorous and ardent style of the original. The text-books also frequently quote him incorrectly, and have thus helped to spread erroneous notions not only of what he said, but of the facts themselves.

HERSCHEL'S long life was all too short, and his assistance was too small to allow him to put even his published work into a final definite form. He has once given us a hint of what he desired, and it seems scarcely less than a duty for his successors to carry out his wishes.

At the end of his memoir of 1811, HERSCHEL added a synopsis of its contents made paragraph by paragraph; this synopsis (which is given at pages 87-89 of this work) serves to summarize and to enforce his views, and to condense his arguments. His style lends itself to this condensation. The synopsis of 5 pages contains all the material facts of the main paper of 67 pages, and the course of the argument can be plainly followed.

In the absence of an edition of HERSCHEL'S collected works, a want whose fulfillment still seems far off, we have thought that we could hardly render a better service than to carry out for all of his writings the idea which he executed for only one. The model has been set by himself. We have simply followed this, and have given a synopsis of each of his memoirs in the Philosophical Transactions, following his own plan. The papers on astronomical subjects have been condensed by Professor HOLDEN; those on physics by Dr. HASTINGS. The works of HERSCHEL published elsewhere have not been included in the synopsis, as they are comparatively unimportant.

It is not supposed that such synopses as these will replace the original memoirs for the professional astronomer and physicist. The works of a great philosopher to be truly mastered must be studied in the form in which he gave them. Yet those who are most familiar with the originals will find the present volume most valuable.

The full subject-index will direct attention to special points. It is hoped that the work in its present form will be of service in various ways, which do not need suggestion here.

EDWARD S. HOLDEN.
CHARLES S. HASTINGS.

WASHINGTON, October, 1880.

II.-LIST OF THE PUBLISHED WRITINGS OF WILLIAM HERSCHEL ON ASTRONOMICAL SUBJECTS.

[IN CHRONOLOGICAL ORDER.]

[N. B. In general, translations and abstracts of these which appeared in periodicals are not noticed here. We have made exceptions in the more important cases.]

[Solution of a prize question.]

Astronomical observations on the periodical star in Collo Ceti.

Ladies' Diary, 1799.

Phil. Trans., 1780, p. 338.

Astronomical observations relating to the mountains of the moon.

Phil. Trans., 1780, p. 507.

Astronomical observations on the rotation of the planets round their axes, made with a view to determine whether the earth's diurnal motion is perfectly equable. Phil. Trans., 1781, p. 115.

Account of a comet. [Dated 13th March, 1781. This was Uranus.]

On the parallax of the fixed stars.

Phil. Trans., 1781, p. 492.

Phil. Trans., 1782, p. 82.

Catalogue of double stars.

Phil. Trans., 1782, p. 112; translation in Bode's Jahrbuch, 1786, p. 187. Description of a lamp micrometer and the method of using it.

Phil. Trans., 1782, p. 163. A paper to obviate some doubts concerning the great magnifying powers used. Phil. Trans., 1782, p. 173.

A letter from WILLIAM HERSCHEL, Esq., F. R. S., to Sir JOSEPH BANKS, Bart., P. R. S. Phil. Trans., 1783, p. 1.

Aus einem Schreiben des Hrn. HERSCHEL an mich [BODE], datirt London, den 13ten August, 1783.

[This is a letter forwarding HERSCHEL'S memoir on the Parallax of the Fixed Stars, etc.]

Bode's Jahrbuch, 1786, p. 258.

On the diameter and magnitude of the Georgium Sidus, with a description of the dark and lucid disk and periphery micrometers.

Phil. Trans., 1783, p. 4.

On the proper motion of the sun and solar system, with an account of several changes that have happened among the fixed stars since the time of Mr. FLAMSTEED. Phil. Trans., 1783, p. 247. Bode's Jahrbuch, 1787, p. 194, p. 224. Astronomische Nachrichten und Entdeckungen aus einem französischen Schreiben desselben an mich [BODE], datirt Datchet nahe bey Windsor, den 18 May, 1784. [This letter is on the subject of the use of high magnifying powers, and gives a résumé of his recent papers.] Bode's Jahrbuch, 1787, p. 211.

On the remarkable appearances at the polar regions of the planet Mars, the inclination of its axis, the position of its poles, and its spheroidical figure; with a few hints relating to its real diameter and atmosphere.

Phil. Trans., 1784, p. 233.

Account of some observations tending to investigate the construction of the heavens. Phil Trans., 1784, p. 437.

[Bode's Jahrbuch, 1788, p. 246, has a summary of this paper by Baron von ZACH. See also, Bode's Jahrbuch, 1794, p. 213.]

Catalogue of double stars.

On the construction of the heavens.

Phil. Trans., 1785, p. 40.

Phil. Trans., 1785, p. 213. Bode's Jahrbuch, 1788, p. 238. See also same, 1787, p. 213, and 1794, p. 213.

Aus einem Schreiben des Hrn. HERSCHEL an mich [BODE], datirt Clay Hall, nahe bey Windsor, den 20 Jul., 1785.

[This is a letter forwarding two memoirs, and giving the prices of telescopes.] Bode's Jahrbuch, 1788, p. 254.

Catalogue of one thousand new nebula and clusters of stars.

Phil. Trans., 1785, p. 457. Bode's Jahrbuch, 1791, p. 157, and same, 1794, p. 213. Investigation of the cause of that indistinctness of vision which has been ascribed to

the smallness of the optic pencil.

Remarks on the new comet [1786, II].

Phil. Trans., 1786, p. 500.

Phil. Trans., 1787, p. 4.

[Letter from HERSCHEL to BODE on the discovery of two satellites to Uranus, dated Slough, 1787, Feb. 11.]

Bode's Jahrbuch, 1790, p. 253. round the Georgian planet. Phil Trans., 1787, p. 125. Bode's Jahrbuch, 1791, p. 255.

An account of the discovery of two satellites revolving

An account of three volcanoes in the moon.

Phil. Trans., 1787, p. 229. Note on M. MÉCHAIN'S comet. [1787, I.] [Added to

On the Georgian planet and its satellites.

Bode's Jahrbuch, 1791, p. 255. preceding paper.]

Phil. Trans., 1787, p. 232.

Phil. Trans., 1788, p. 364. Bode's Jahrbuch, 1793, p. 104.

Observations on a comet [1788, II. ].

Phil. Trans., 1789, p. 151. clusters of stars, with a few introductory remarks on the construction of the heavens. Phil. Trans., 1789, p. 212. Bode's Jahrbuch, 1793, p. 150. Also same, 1794, p. 150. Account of the discovery of a sixth and seventh satellite of the planet Saturn, with remarks on the construction of its ring, its atmosphere, its rotation on an axis, and its spheroidical figure.

Catalogue of a second thousand of new nebula and

Phil. Trans., 1790, p. 1. Bode's Jahrbuch, 1793, p. 239; same, 1796, p. 88; 1797, p. 249.

On the satellites of the planet Saturn, and the rotation of its ring on an axis.
Phil. Trans., 1790, p. 427.

On nebulous stars properly so called.

Phil. Trans., 1791, p. 71.

Bode's Jahrbuch, 1801, p. 128.

On the ring of Saturn and the rotation of the fifth satellite upon its axis.
Phil. Trans., 1792, p. 1.

Bode's Jahrbuch, 1796, p. 88.

Miscellaneous observations:

[Account of a comet], p. 23 [1792, I.].

[On the periodical appearance of o Ceti], p. 24.

[On the disappearance of the 55th Herculis], p. 26.

[Remarkable phenomenon in an eclipse of the moon], p. 27.

Observations on the planet Venus.

Observations of a quintuple belt on the planet Saturn.
Phil. Trans., 1794, p. 28.

Phil. Trans., 1792, p. 23.

Phil. Trans., 1793, p. 201.

Bode's Jahrbuch, 1798, p. 90. Account of some particulars observed during the late eclipse of the sun. [1793, September 5th.]

On the rotation of the planet Saturn upon its axis.

Phil. Trans., 1794, p. 39.

Phil. Trans., 1794, p. 48. Bode's Jahrbuch, 1798, p. 74. On the nature and construction of the sun and fixed stars.

Phil. Trans., 1795, p. 46. Bode's Jahrbuch, II. Suppl. Band, p. 65.

Description of a forty-foot reflecting telescope.

Phil. Trans., 1795, p. 347. Bode's Jahrbuch, III. Suppl. Band,
[1796, I.]

Additional observations on the comet.

p. 238. Phil. Trans., 1796, p. 131.

On the method of observing the changes that happen to the fixed stars; with some remarks on the stability of the light of our sun. To which is added a catalogue of comparative brightness for ascertaining the permanency of the luster of stars. Phil. Trans., 1796, p. 166. Bode's Jahrbuch, 1809, p. 201.

On the periodical star a Herculis; with remarks tending to establish the rotary motion of the stars on their axes; to which is added a second catalogue of the comparative brightness of the stars.

Phil. Trans., 1796, p. 452. Bode's Jahrbuch, 1809, p. 201. A third catalogue of the comparative brightness of the stars, with an introductory account of an index to Mr. FLAMSTEED's observations of the fixed stars, contained in the second volume of the Historia Cœlestis. To which are added several useful results derived from that index.

Phil. Trans., 1797, p. 293. Bode's Jahrbuch, 1810, p. 143. Observations of the changeable brightness of the satellites of Jupiter, and of the variation in their apparent magnitudes, with a determination of the time of their rotatory motions on their axes. To which is added a measure of the diameter of the second satellite, and an estimate of the comparative size of all the four.

Phil. Trans., 1797, p. 332. Bode's Jahrbuch, 1801, p. 103. On the discovery of four additional satellites of the Georgium Sidus. The retrograde motion of its old satellites announced, and the cause of their disappearance at certain distances from the planet explained.

Phil. Trans., 1798, p. 47. Bode's Jahrbuch, 1801, p. 231. the stars.

A fourth catalogue of the comparative brightness of

Phil. Trans., 1799, p. 121. Bode's Jahrbuch, 1810, p. 143.

On the power of penetrating into space by telescopes, with a comparative determination of the extent of that power in natural vision, and in telescopes of various sizes and constructions, illustrated by select observations.

Phil. Trans., 1800, pp. 49-85. Bode's Jahrbuch, 1804, p. 231.

Investigation of the powers of the prismatic colors to heat and illuminate objects, with remarks that prove the different refrangibility of radiant heat. To which is added an inquiry into the method of viewing the sun advantageously with telescopes of large apertures and high magnifying powers.

Phil. Trans., 1800, pp. 255–283. Bode's Jahrbuch, 1804, p. 89.

Experiments on the refrangibility of the invisible rays of the sun.

Phil. Trans., 1800, pp. 284-292. Bode's Jahrbuch, 1804, p 89. Experiments on the solar and on the terrestrial rays that occasion heat, with a comparative view of the laws by which light and heat, or rather the rays that occasion them, are subject, in order to determine whether they are the same or different. Phil. Trans., 1800, pp. 293-326, 437-538. Gilbert Annal., X. (1802), pp. 68-78;

same, XH. (1803), pp. 521-546.

Observations tending to investigate the nature of the sun, in order to find the causes or symptoms of its variable emission of light and heat, with remarks on the use that may possibly be drawn from solar observations.

Phil. Trans., 1801, pp. 265–318. Bode's Jahrbuch, 1805, p. 218, and 1805, p. 113. Ueber den 7 Nebelfleck der 1sten Classe des Herschel'schen Verzeichniss, und über Ceres und Pallas, vom Herrn Doctor HERSCHEL, aus zwey Briefen desselben. Bode's Jahrbuch, 1805, p. 211.

Additional observations tending to investigate the symptoms of the variable emission of the light and heat of the sun, with trials to set aside darkening glasses by transmitting the solar rays through liquids, and a few remarks to remove objections that might be made against some of the arguments contained in the former paper. Phil. Trans., 1801, pp. 354-332.

Observations on the two lately discovered celestial bodies [Ceres and Pallas].
Phil. Trans., 1802, pp. 213-232. Nicholson Journal, IV. (1808), pp. 120-130, 142–

148.

Catalogue of five hundred new nebula, nebulous stars, planetary nebulæ, and clusters of stars, with remarks on the construction of the heavens.

Phil. Trans., 1802, pp. 477-528. Bode's Jahrbuch, 1807, p. 113. Observations of the transit of Mercury over the sun's disk, to which is added an investigation of the causes which often prevent the proper action of mirrors. Phil. Trans., 1803, pp. 214-232. Account of the changes which have happened during the last twenty-five years in the relative situation of double stars, with an investigation of the cause to which they are owing.

Phil. Trans., 1803, pp. 339–382. Bode's Jahrbuch, 1808, pp. 154-178. Continuation of the account of the changes that have happened in the relative situation of double stars.

Phil. Trans., 1804, pp. 353-384. Bode's Jahrbuch, 1808, p. 226. Aus einem Schreiben des Herrn Doctor HERSCHEL, datirt Slough bey Windsor, den 31 May, 1804.

[Relates to his theory of the relation between the solar radiation and the price of wheat.]

Bode's Jahrbuch, 1808, p. 226.

Experiments for ascertaining how far telescopes will enable us to determine very small angles, and to distinguish the real from the spurious diameters of celestial and terrestrial objects, with an application of the results of those experiments to a S. Mis. 31- -33