Bauhaus-Universität Weimar

Reports of Visits to Foreign Laboratories, vol. 1 (1907) [Illustrated Typoscript in 7 volumes] Reproduced with the kind permission of Dr. Cecil E. Leith
Benedict, Francis Gano
Prof» Hagem.Jim has’ likewise attempted to measure the diff¬ 
erences in temperature of the water current "by resistance ther¬ 
mometers. The water at Bonn is extremely unsatisfactory, con¬ 
taining a great deal of sediment and with the thermometers he 
has tried, i* soon clogs up and becomes short-circuited. 
Suggestion. The new platinum resistance thermometers of 
Heraeus. enclosed in fused quartz tubes, should be especially 
advantageous for measuring the temperatures of the ingoing and 
outcoming water current. According to Wrede in Berlin, these 
resistance thermometers are extremely sensitive. Their use 
is to be thoroughly investigated in the construction of our 
new chambers. 
Temperature of air current.—-In order to measure the differ¬ 
ence in temperature between the ingoing and outcoming air current, 
Prof. Hagemann uses both thermal junctions nd resistance ther¬ 
mometers but the latter were, at the time of my visit, out of 
order. He feels very dissatisfied with the thermal junctions. 
Very long junctions are used and Prof. Hagemann feels convinced 
that there v/as heat conducted along the junction wires through 
the vestibule and hence there was an error. His present system 
is very complicated and I fail to see that it is any more effec¬ 
tive than that we were using at Middletown. 
I suggested a scheme we have in miad for the new apparatus 
of having the ingoing c~ir go», in. in a tube encircling the out¬ 
coming air and thus use the outcoming air as a regulator of the 
te werature of the ingoing air. 
For regulating the temperature of the air, Prof. Hagemann 
has a large water cooling tank such as was used in the Middletown 
apparatus, very much enlarged. He also has an electrical heating


Sehr geehrte Benutzer,

aufgrund der aktuellen Entwicklungen in der Webtechnologie, die im Goobi viewer verwendet wird, unterstützt die Software den von Ihnen verwendeten Browser nicht mehr.

Bitte benutzen Sie einen der folgenden Browser, um diese Seite korrekt darstellen zu können.

Vielen Dank für Ihr Verständnis.