APRIL 14, 1904] 
NATURE 
573 
and the examinations at each of the twelve technical schools | 
for special branches of the metal industries which have been 
established in Germany. 
Tue thirty-ninth annual catalogue of the Massachusetts 
Institute of Technology at Boston gives full particulars of 
the multitudinous courses of instruction provided and of 
the complete laboratory accommodation and equipment avail- 
able for every branch of scientific technology. In addition 
to the opportunities for advanced study and investigation 
connected with the Graduate School of Engineering Re- 
search, the institute now offers excellent facilities for purely 
Scientific research in all its laboratories. For research 
work in physical chemistry and sanitary science two new 
laboratories devoted exclusively to these subjects have been 
established during the past year. Researches in the re- 
search laboratory of physical chemistry are carried on in 
part by a staff of research assistants and associates and in 
part by graduate students working under the direction of 
the professors connected with the subjects of theoretical 
or physical chemistry. A number of advanced lecture 
courses are offered by the members of the laboratory staff. 
B» the generosity of an anonymous donor the institute has 
recently established upon land specially secured for the 
purpose a sanitary research laboratory and sewage experi- 
ment station, provided with facilities for demonstration of 
the more important methods employed on a large and a 
small scale for the purification of sewage and water, and in 
connection therewith well equipped sanitary, chemical, and 
bacteriological laboratories. 
Tue Department of Agriculture and Technical Instruction 
for Ireland has issued, in the miscellaneous series of its 
Bulletins, a report on some features of American education, 
by Mr. Robert Blair, the assistant secretary in respect of 
technical instruction to the department. Mr. Blair was a 
member of the Mosely Education Commission, and part of 
this report appears in the recent conjoint report of the com- 
mission. Some interesting statistics collected by Mr. Blair 
as to the openings for students trained in 
technical institutions are summarised in the report. It 
appears that in the Westinghouse shops and offices 160 
college-bred men are engaged, out of a total of 10,000 
employees. At the Carnegie Steel Works, where there are 
7000 hands, there were about 100 technically trained men, 
7 of the 23 leading officers being college graduates. Of 
118 engineers on the staff of the Rapid Transit Railroad 
Commissioners of New York City, who are constructing 
a city underground railway, 84 per cent. had been college 
students; of 75 petty officers, 58 per cent. were college 
trained. In the Baldwin Locomotive Works, 43; on the 
Pennsylvania railway lines west of Pittsburg, 52, ‘‘ nearly 
all being graduates ’’; at the Schenectady works of the 
General Electric Co., 264; the Illinois Central Railroad Co. 
employ 200 men who are “‘ either graduates of a technical 
institution or have had some training in that line’’; and 
a similar proportion is true in the case of the employees of 
the Baltimore and Ohio Railway. Facts such as these are 
the best proof of the belief of the American people in higher 
education, and it is to be hoped that British employers of 
labour will soon follow a similar course. Given suitable 
openings for qualified technical students in this country, and 
the increase in the number of students in our colleges would 
soon be apparent. 
SOCIETIES AND ACADEMIES. 
Lonpon. 
Royal Society, February 18.—‘‘ Atmospherical Radio- 
activity in High Latitudes.’”’ By George C. Simpson, 
B.Sc., 1851 Exhibition Scholar, Owens College, Manchester. 
Communicated by Arthur Schuster, F.R.S. 
In 1901 Elster and Geitel discovered a radio-active gas in 
the earth’s atmosphere, and developed a method of detecting 
it, also an arbitrary standard by which it can be measured. 
In this paper the author gives the results of a series of 
measurements carried out on Elster and Geitel’s plan at the 
village of Karasjok, Lapland. The measurements were 
made three times a day, and continued uninterrupted for 
four weeks, from November 23 to December 19, 1903, during 
which time the sun did not rise above the horizon. 
NO. 1798, VOL. 69 | 
American | 
The chief result obtained is the very high value which the 
| radio-activity attains, the mean value for the month 
(A=102) being nearly six times, and the maximum value 
(A=432) nearly seven times greater than the corresponding 
values found for mid-Germany by Elster and Geitel. 
An analysis of the results shows that the means of the 
morning and afternoon observations are very near one 
another (87 and 88 respectively), while the mean of those 
for the evening is very much higher (131), thus showing 
a daily period. 
The effect of the different meteorological elements is fully 
investigated, but no connection can be detected between the 
radio-activity and the height of the barometer or the 
temperature, although the latter extends over the wide range 
from —35° to +2-5° C. On the contrary, the amount of 
cloud does appear to have an influence, the radio-activity 
for no clouds being A=130, for detached clouds A=107, 
for completely overcast sky A=7 Measurements of the 
potential gradient, which were made by a self-registering 
electrometer concurrently with those of the radio-activity, 
show no direct relation between the two. The aurora also 
appears to exert no influence on the radio-activity. 
These results are of peculiar interest owing to the 
northerly position of the place of observation (69° 20’ N. 
and 25° 30’ E.), and will throw some light on the geo- 
graphical distribution of atmospheric radio-activity. The 
hard frozen state of the ground, with its covering of snow 
for more than 100 miles round, are uniform conditions which 
should help to a proper understanding of the source of the 
radio-active emanation in the air. 
10o.—* On Electric Resistance Thermometry at 
1 By Prof. James 
March 
the Temperature of Boiling Hydrogen. 
Dewar, M.A., LL.D., F.R.S. 
In his Bakerian lecture the author adverted shortly to 
some results obtained in low temperature resistance thermo- 
metry, and gave a table (Roy. Soc. Proc., vol. Ixviii. p. 363) 
of numerical values deduced from experimental observations 
for some of the more prominent metal resistance thermo- 
meters. In the present communication the experimental 
records of eight additional electric resistance thermometers 
are given, and the results of the observations on all the 
resistance thermometers used during the investigations are 
collected and compared. 
Two facts seem to result from this inquiry, viz. (1) that 
the resistance of an unalloyed metal continually diminishes 
with temperature and in each case appears to approach to 
a definite asymptotic value below which no further lower- 
ing of the temperature seems to reduce it; and (2) that the 
parabolic connection between temperature and resistance is 
no longer tenable at very low temperatures. 
Of the different thermometers constructed on the electric 
resistance principle, fifteen were serviceable throughout the 
investigations; the others broke or failed from various 
causes. The metals employed were platinum, gold, silver, 
copper, palladium, iron, nickel, and two alloys, platinum- 
rhodium and German silver. Every endeavour was made 
to attain the highest purity in the samples. In the Bakerian 
lecture a table (Roy. Soc. Proc., vol. Ixviii. p. 363) was 
given containing the constants of seven of these thermo- 
meters, and in the present paper similar results are tabulated 
for the remaining eight. 
The observed resistances, after all corrections were made, 
were reduced both by Callendar’s and by Dickson’s methods, 
and the results are in close accord. 
Platinum, gold, silver, and copper show a remarkable 
agreement between the two methods of reduction. In the 
platinum and gold groups the centigrade temperature, at 
which the resistance would vanish, rises with the purity. 
This is still seen in copper, but something of the reverse 
appears in the case of silver. However, the general rule is 
again apparent in palladium. 
It is also remarkable that in the cases of all the purest 
metals examined, their resistances calculated by either 
method of reduction vanish at temperatures above —273° C. 
As measurers of temperature gold and silver seem to be 
the best metals. 
As a matter of interest, one line in the table. which 
accompanies the paper records the ratio in which the 
1 Jn continuation of Art. 3 of the Bakerian Lecture (Roy. Soc.Proc., 
vol. Ixviii. p. 360.) 
