366 
NATURE 
[JUNE 4, 1914 
THE *UTILISATION, OF (SOLAR VE NENG ies 
FTER naming the principal workers in this field, 
the author gives determinations of the solar con- 
stant and deals fully with the varving percentages of 
this quantity that are available throughout the day for 
power purposes. He then describes four types of 
Shuman sun heat absorbers and gives in great detail 
the results of his forty-eight trials of these absorbers, 
the latest pattern (that erected near. Cairo, Egypt) of 
which gave a maximum thermal efficiency of no less 
than 40-7 per cent., and a maximum output of steam 
of -1442 lb. an hour at a pressure of 15-8 lb. per 
sq. in. abs. The results of these types of absorbers 
are compared by means of tables and curves, and from 
these the author has constructed a formula by means 
of which it is easy to calculate for a given type and 
size of absorber the total output of steam an hour 
if three things are known: (1) the time of day; (2) the 
humidity; and (3) the steam pressure. It has been 
known that humidity adversely affects the quantity of 
solar radiation arriving at the earth’s solid surface, 
but this is the first time that its effect on solar steam 
production has been quantitatively determined, ' 
The Meadi Absorber. 
Looking .N.E. and showing the reflectors in the mid-day position. 
showing that the Shuman engine is the more 
economical. The steam consumption of one of these 
engines was only 22-1 lb. per B.H.P. hour, when the- 
output was 945 B.H.P., and the steam pressure only 
16-2 Ib. per sq. in. abs. The thermal efficiency of, 
the engine compared with an engine working on the 
Rankine cycle was‘ 54:75 per cent. In the case of a 
Shuman high-pressure non-condensing engine with. 
an output of 29 B.H.P., the steam consumption was. 
238 lb. per -B.H.P. hour, and the relative thermal 
efficiency 71-7 per cent. 
Finally the author gives the results of his trials of 
the complete sun power irrigation plant at Cairo, and 
describes his design of a special form of weir tank 
for measuring greatly differing quantities of water. 
UNIVERSITY AND EDUCATIONAL 
INTELLIGENCE. 
CamBRIDGE.—Dr. W. H. R. Rivers has been ap- 
pointed to represent the University at the nineteenth 
International Congress of Americanists to be held ‘at 
Washington, U.S.A., in October next. 
There are 5 reflectors each 205 ft. long, 
and 13 ft. 5 in. wide at the top. 
The difference between the thermal efficiency of the 
solar boiler and the commercial value of the steam 
produced is ingeniously brought out, the author 
making it clear that in the case of such low-pressure 
boilers a high thermal efficiency is not necessarily the 
same thing as the most economical conditions of 
working, and he shows that, up to a certain limit, the 
higher the steam pressure, the more economical the 
working, though the thermal efficiency is then lower. 
Two of the types of absorber did not move with the 
sun, and one did. The greater constancy of output of 
steam in the case of the latter is very marked. | 
In order to utilise the low-pressure steam economic- 
ally, Mr. Frank Shuman designed a special engine 
which has also gone through several stages. This 
engine is fully described with drawings, and the 
author gives the results of his fourteen trials of the 
several engines and compares their results with those 
of exhaust steam turbines and the low-pressure 
cylinders of compound- and triple-expansion engines, 
1 Summary of a paper read before the Society of Engineers (Incor- 
porated) on April 6, by Mr. A. S. E. Ackermann. 
NO. 2327 s:ViOrsto3 | 
The Special Board fer Biology and Geology has 
nominated Dr. Shipley as the representative of the 
University on the council of the Marine Biological 
Association. 
The Sudbury Hardyman prize offered for an original 
dissertation by a graduate member of Emmanuel Col- 
lege under the standing of M.A., has been awarded 
to Mr. G. Matthai, for a treatise entitled ‘‘ A Revision 
of the Recent Colonial Astraeidae Possessing Distinct 
Corallites.”’ 
OxrorD.—The Halley Lecture in 1915 will be de- 
livered by Dr. F. W. Dyson, F.R.S., late fellow of 
Trinity College, Cambridge, Astronomer Royal. 
The Hon. Bertrand A. W.. Russell, F.R.S., late 
fellow of Trinity College, Cambridge, has been elected 
Herbert Spencer lecturer for the year 1914-15. 
The Romanes Lecture, as previously announced, 
will be delivered by Sir J. J. Thomson, O.M., F.R.S., 
on June 10, at 3 o’clock. . Subject, ‘‘The Atomic 
Theory.’ 
Dr. C. W. CHAMBERLAIN has been inaugurated presi- 
