SCIENCE.
��THE ROYAL ASTRONOMICAL SOCIETY OF LONDON.
Tais Jioclety, tli€ moat impiirlant astronomical orgftniEatlon In existence holding frequent meetings, bad Its annlTersary sesaion on Fub. 13, on which occasion tba principal event nas the presentation of tbe gold medal to Dr. William Ilugglns for hit spec- troscopic researches, as already anuoniiced. The ' Monthly notice ' which gives account of this meet- ing is usually the most interesting number for the year, and the present Issue is not disappointing In this regard. The society, which was organized about the year IS20, is possessed of a good degree of wealth, aggregating considerably more than a hundred thou- sand dollars, of which about seventy thousand are, pecuniarily remunerative. Not a small amount of the society's properly is In the sbape oE astro iioni leal and other instruments of precision, a. catalogue of which Is regularly pultlisbed, and embraces this year a List of a hundred and twentj-one entries. The publications of the society have now reached the forty-flfth volume of ' Monthly notices,' and of the ' Memoirs' the forty-eighth. The second pari of this latter volame is now In pre»B, and is announced to contain Mr. Seabroke's fourth catalogue of micro- metric messures ot doubieslars. Professor Prltchanl's determination of the relative proper molloa of forty stars In the Pleiades, Mr. Kiiobel's observations ot Mars In 1884, and two memoirs relative to the moon, — the one by Mr. Nelson on the corrections required by Hansen's ■ Tables,' and the other by Qogou on an inequality of long-period in its motion.
The council of the society record the loss by death, during the year, of fifteen fellows and one associate: an exceptional number of these are men of wide reputation, and the obituary records are exceptionally well wrilleu. We note only Henry George Bohn, John Henry Dallmeyer, Isaac Todhunter, Francis DIedrich Wackerbarth, Ernst Frledrlcb Wilbelm Kliukertues, Marian Kowalski, and Johann Frledrich Julius Schmidt. In general, the ' Proceedings ot ob- ■ervatories' are not more Interesting than formerly; and, of the twenty-one institutions reported, a small number appear to be gradually foislllziiig, while at two, or three an entraordinary degree of activity Is evinced. American astronomers will find slender cause for complainiiigatthecouncil's"Noteson some points connected with the progress ot astronomy during the past year; ' ' tor alrout one-half ot the sec- tion of twenty-seven pages devoted to this history is occupied with the work of Americans in the advance- ment of this science. The important ' points ' com- mented upon are Professor Newcomb's reseiirchea in mathematical astronomy, Professor SaSord's Inves- tigation of Greenwich planetary observations, star catalogues by Dr. Gould and Dr. Grant, Dr. Back- lund's Investigailon of the motion of Bncke's comet, Derabowskl's measures of double stars. Professor Pickering's work with the meridian photometer, Dr. Muggins's photography of the solar corona without an eclipse. Professor Langley's researches In
��atmospheric absorption, and the conclusions of the International prime- meridian conference.
At the conclusion of the anniversary meeting, Mr. Edwin Dun kin was re-elected president of the society; and Professor Adams, Professor Cayley, Dr. De la Bue, and Mr. Stone were elected vice-presidents.
��JAMES CLERK MAXWELL.
This abridged volume will be welcoiDed with great pleasure by all who have enjoyed the larger work, for it puts into one's hands a vade mec-um. The life of Maxwell is worth pondering upon ; and it ia a peculiarity of all that he has ever written upon science, that some miuds can draw inexhaustible nour- ishment from his essays and letters. Many will misa portions of the larger volume ; but, in return for what has been omitted, the editors Jiave given three important letters from Clerk Maswell to Faraday, and one of Faraday's to him. The volume also contains letters to Dr. Huggina on the structure of comets. Hia let- ter to Faraday, upon the latter's idea of lines of force. Shows clearly how strongly the new conception had taken possession of his mind. In this letter he says, —
" Toil have also seen that the great mystery is, not how like bodies repel and unliiie attract, but how like bodies attract by gravitation. But U you can get over that difficulty, either by making gravity the residual of the two electricities ot by simply admit- ting it, then your lines of force can ' weave a web across the sky,' and lead the stars in iJieir courses, without any necessarily immediate connection with the objects of their attraction."
It ia highly interesting to read the letters which passed between these distinguiahed men. It was perfectly natural for Maxwell to cxpreas his physical ideas in mathematical language ; while Faraday, unversed in mathematics, could nevertheleas express hia conclusions in a logical shape, which were the translations into ordinary language of the results of Max- well's equations. In one place Faraday writes, —
" There Is one thing I would be glad lo apk you. When a mathematician, engaged in Investigating physical actions and results, has arrived at his con- clusions, may they not be expressed in common language as fully, clearly, and definitely as In math- ematical formulae ? If so, would It not be a great iKion to such as 1, to express them so, translating them out of their hieroglyphics, that we also might ' erfment?"
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