436 
ulation Board, which determines the admission 
of students to the five northern universities 
and examines and inspects secondary schools 
in their areas of influence; also of the Man- 
chester Royal College of Music, of the Man- 
chester Royal Institution, and of the newly 
formed northern branch of the National Li- 
brary for the Blind. 
He has been for many years a fellow and 
governor of Eton College, and fellow of Mag- 
dalen College, Oxford; was elected a fellow of 
the Royal Society in 1896; has been president 
of the Mineralogical Society, and of the Geo- 
logical and Educational Sections of the Brit- 
ish Association; is an honorary doctor of the 
universities of Sheffield and Christiania; was 
knighted in 1912; was a member of the treas- 
ury committee which reported on the reform 
of the Civil Service Class I examinations; 
and is a member of the committee appointed 
by the prime minister to report on adult edu- 
cation. 
During and since college days he has de- 
voted most of his vacation to foreign travel. 
In 1892, while assistant at the British Mu- 
seum, he visited and reported on the public 
and private mineral collections of Norway, 
Sweden and Russia and part of Germany. 
In 1901 he joined Professor Coleman of 
Toronto in Canada for a journey of explora- 
tion in the northern Rockies, but at the in- 
yitation of the Canadian Minister of the In- 
terior changed his plans and visited and re- 
ported on the gold mines of Klondike, in 
company with Professor Coleman. He had 
previously visited Canada and the Pacific 
coast with the British Association (spending 
some weeks also in the United States) in 
' 1897; and was there again with the Interna- 
tional Geological Congress in 1913. 
He visited a great part of South Africa on 
the invitation of the Rhodes trustees and the 
Johannesburg Council of Education in 1903, 
and was personally concerned in the first ap- 
pointments made in the Transvaal Technical 
Institute which afterwards became the Trans- 
yaal University College. A second visit to 
South Africa with the British Association 
took place in 1905. 
SCIENCE 
[N. 8. Vou. XLVIII. No, 1244 
Many of his European journeys have been 
made to places which possess public or pri- 
vate collections of antique sculpture, in which 
he is interested. 
DR. JOHN JOLY 
John Joly, M.A., B.A., Engineering, D.Se., 
has been professor of geology and mineralogy 
in the University of Dublin for the past twenty 
years. He was born in Ireland in 1857 and 
educated at Trinity College, in which he held 
various subordinate posts before his appoint- 
ment to the chair which he now occupies. 
For more than thirty years he has carried 
on research in physics, and especially in the 
application of physics to engineering, but his 
exceedingly ingenious mind has led him down 
many by-paths in search of the solution of 
problems of general interest. } 
One of his earliest inventions was the steam 
calorimeter, by means of which he succeeded in 
determining directly the specific heats of gases 
at constant volume. This was a problem in ex- 
perimental science which had long baffled 
physicists. Having invented the calorimeter, 
Joly turned it to excellent account in the ex- 
amination of a variety of gases over a wide 
range of pressure and temperature. 
Distinguished as a physicist, he is more 
widely known as a pioneer in the modern 
method of photography in colors. He was the 
first in 1897 to take successful photographs in 
natural colors by the use of a minutely-sub- 
divided screen carrying the three primary 
colors. On a plate exposed behind this screen 
he obtained, in effect, three negatives on the 
same plate. A transparency made from .this 
plate, when placed in an optical lantern behind 
a screen similarly ruled in red, green and blue 
lines, displayed the objects photographed in 
their natural colors. This experiment led, ten 
years later, to the development of the well- 
known and very efficient Lumiére process on 
which colored starch grains are substituted for 
Joly’s colored lines. 
The ascent of sap in trees is another subject 
which has occupied his attention, in conjune- 
tion with Henry H. Dixon, the professor of 
botany of Trinity College. He offered a simple 
