574 
NATURE 
[JANUARY I5, 1974 
telescope is focussed on the incandescent body, thus 
bringing its image into the plane AC. The current 
is then adjusted by means of the rheostat until the 
filament is of the same colour and brightness as the 
object. A previous calibration of the current for the 
particular lamp used, in terms of temperature, will 
then give the temperature of the hot body. 
Radiation pyrometers differ from the optical types 
previously discussed in that they employ all the radia- 
tion received from the hot body. The first practical 
form of pyrometer making use of total radiation was 
invented by Féry. The instruments is shown in section 
in Fig. 5. The radiation from the hot body is 
focussed by means of the concave mirror on to a 
sensitive thermo-couple mounted at D; the electro- 
motive force generated by 
the couple is indicated on a 
galvanometer connected to 
the terminals, B, B In 
another form of the instru- 
ment Féry has replaced the 
thermo-couple by a_ bi-metallic 
spiral placed in the focus 
of the mirror. When heated 
the spiral uncoils and carries 
an aluminium pointer over a 
dial divided in degrees of tem- 
perature. 3 
aR 
CONCAVE MIRROR 
INCLINED MIRAQi'§ ————* 
WMA 
TNH LR BO a 
Fic, 5.—Diagram of Féry radiation pyrometer. 
The author discussed briefly the capabilities and 
limitations of the optical and radiation pyrometers 
with the view of assisting observers in their use. He 
also threw out suggestions as to the best forms of 
pyrometer to be used in various industrial operations. 
In discussing the question of the standardisation 
of pyrometers, the author pointed out that unless 
pressed for time the observer would find it advis- 
able to send his instruments to the National Physicai 
Laboratory, when they would be examined and their 
corrections determined for a moderate fee. In a 
works where there are a large number of instruments, 
it is advisable to keep a set of instruments which have 
been examined at the National Physical Laboratory 
as standards of reference. If this is not possible, 
corrections at one or two points in the range of the 
thermometer can generally be determined. The author 
mentioned the boiling points of some liquids and the 
freezing points .of some pure metals and salts which 
would be found useful as standardisation points. 
NO. 2307, VOL. 92] 
GALV/NOMETER —— ae 
Si 
A SSSI 
THERMO COUPLE 
SSSA SSSSSEAS NUS SS SASS 
UNIVERSITY AND EDUCATIONAL 
INTELLIGENCE. 
CAmBripGE.—Dr. H. F. Baker, F.R.S., fellow and ~ 
lecturer of St. John’s College, and Cayley university 
lecturer in mathematics, has been elected Lowndean 
professor of astronomy and geometry in succession to 
the late Sir Robert Ball. 
Dr. Livincston Farranp, professor of anthropology 
at Columbia University since 1903, became president 
of the University of Colorado on New Year’s Day. 
A native of Newark, New Jersey; he graduated at 
Princeton in 1888, and, after completing a medical 
course in America, studied for two years at Cambridge 
and Berlin, before receiving 
an appointment as instructor 
in psychology at Columbia 
in 1893. j 
Iv is proposed to establish 
a club for graduates, 
teachers, and officers of the 
University of London. The 
proposal has been approved 
by the Senate of the Univer- 
sity and by Convocation. 
Negotiations are in progress 
for the lease of 19 and 21_ 
Gower Street, W.C., and, 
subject to a _ satisfactory 
assurance as to the number of 
members joining the club if 
Uy 
CK 
Organisation Committee is willing 
to continue negotiations. The 
adaptation of the premises will 
take some time to carry out, but 
it is hoped that the club may be 
open to members immediately after 
the Easter vacation. The sub- 
scriptions in the first instance wilt 
be two guineas for town members, 
and one guinea for country mem- 
bers. The entrance fee will be 
one guinea, except that the first 
thousand original members will be 
exempt. A form of application for 
admission to original membershi 
may be obtained from Mr. T. LI. 
Humberstone, secretary, Univer- 
sity of London Club Organisa- 
tion Committee, University of 
London, South Kensington, S.W. 
SOCIETIES AND ACADEMIES. 
Lonpon. 
Society of Chemical Industry, January 5.—Dr. 
W. R. E. Hodgkinson in the chair.—J. L. Strevens ; 
The viscosity of oils. The author, after emphasising 
the importance of the determination of absolute vis- 
cosity and its relation to temperature for any particular 
lubricant, proceeds to correct certain figures previously 
published.—L. T. Wright: The oxygen content of the 
gases from roasting pyrites. The author on examin- 
ing a number of analyses of ‘‘burner” gas from 
various sources noticed that the oxygen “ deficiency ” 
is the greater the greater the dilution of the gas, and 
this suggests that there is in addition to the well- 
known production of SO, and metallic sulphates some 
other cause, such as a constant error in the analyses, 
which influences these. In any case, the evidence of 
_ these gas analyses shows that the manner in which 
the oxygen is disposed of would prevent the “ burner” 
established in these premises, the — 
