JOSEPH WINLOCK. 345 



focal length, to be used in the manner just described for instantane- 

 ous photographs. At this time, Mr. Winlock's method was widely 

 known and highly appreciated, and every party which went into the 

 • fieid to observe this eclijjse had decided to dispense with an eye-piece, 

 and photograph in the focus of the object-glass. Unfortunately all the 

 parties, European and American, failed, by reason of bad weather, in 

 obtaining a picture of the corona, except the party in Spain ; and 

 there, also, the sky was not favorable for the best results. All the 

 observers who went to India to photograph the total eclipse of 1871 

 preferred the same method, and were successful. Lord Lindsay 

 applied it at the Mauritius in connection with the horizontal telescope. 

 A telescope of long focus is not a new thing; a telescope placed upon 

 the ground is not a new thing ; there is no novelty about the heliostat ; 

 more than one person may have discovered the advantage in photo- 

 graphing which belongs to telescopes of great focal length. Neverthe- 

 less, the adaptation to photographic purposes of a telescope of long 

 focus, fixed horizontally, and used without an eye-piece or a heliostat, 

 is original, and whatever merit there is in it belongs to Mr. Winlock. 



In a former generation, an eclipse of the sun excited the interest of 

 astronomers, as furnishing the means of verifying or correcting the 

 dynamical theory, or giving differences of geographical longitude. It 

 is the consolation of science, that as fast as old fields are exhausted 

 new ones call loudly for cultivation. As soon as one question is set- 

 tled and curiosity flags, another problem springs into life and a fresh 

 interest is born. The old ambition to fit out a comet with its orbit 

 has yielded to the passion for knowing more about its physical changes 

 and constitution. Now that the law of gravitation asserts an un- 

 challenged supremacy in tlie solar system, the complex structure of 

 the sun and the origin of the solar radiations claim a share of the 

 astronomer's attention. In this way piiysical astronomy has accpiired 

 a new meaning ; and a physical as distinguished from an astronomical 

 observatory, either under the same or an independent superintendence, 

 is one of the necessities of to-day's astronomy. It has been largely in 

 the interest of physical astronomy, in this new sense, that observers 

 have traversed continents, crossed oceans, and taken up their quarters 

 in desolate islands, wherever a total eclipse of the sun or the transit 

 of Venus has invited them. Where special physical observatories 

 liave not been started, the old observatories must assume their work, 

 but not to the prejudice of the preferred duties of an astronomical 

 observatory. Mr. Winlock gave a liberal portion of his time to celes- 

 tial spectroscopy, and stocked the Observatory with the requisite 



