Obituary. 159 
3. Diameter of the Sun.—F rom a discussion of the Greenwich 
observations, 1836-1870, Dr. Fuhg obtains, Astron. Nach., 2040, 
32' 2°"99 as the diameter of the sun deduced from 6827 measure- 
ments. L 
IV. OBITUARY. 
Str Wii1iam Loean, the Geologist, died at London, in June, 
in his eo year, having ‘been born in Montreal in n April, 1798. Sir 
Willia ogan was head of the Geological Surveys of the Can- 
adas res 1843 to 1871. After graduation at the University of 
oS 
London, and late me manager, for the house, of coal mining 
nd copper eg operations in Swansea, where he studied so 
eres ec eld hat region, anes is — and plans 
Vv i commu icated cess valuable papers to the 
Geological Society of London. eological Survey of the 
vinces had its origin in his rese re- 
me a mem 
ber of t homer! Society o fTond on, and of many “oat lomiasedl 
societies. The Wollaston medal of the Geological Society was 
awarded to Mr. Logan in 1856, and he was knighted by Queen 
Victoria in the same year. 
JoserH Wintock was born Feb. 6, 1826, in Shelby County, 
stitution until 1852, The remainder of his life was passed chiefly 
at Cambridge, Mass , but he spent some months at the U.S. Naval 
Observatory in Washington, and for more than a year was at the 
head of the sinsliveaptieal department of the U.S. Naval Academy 
at Annapolis. He was twice made Superintendent of the Ameri- 
can Ephemeris, finally quitting this office in 1866 to take the post 
of Phillips Professor of Astronomy at Harvard University, and in 
that capacity to serve as Director of the Observatory. He held 
- office at the time of his death, June 11, 1875. His last illness 
as short, and did not appear dangerous until a few hours before 
its termination. 
Professor Winlock was an excellent a and astrono- 
) 
concerning those facts. The originality of his mind, however, was 
iefly shown in his suggestions for the i “igh ent of astronom- 
ical aR dn These —— were singularly simple and 
effective. Four among them dese # special notice in this foe. 
(1.) The monekie of large orale circles in such a manne 
to allow the piers to be shortened, so that the graduated ciel 
