3 9 8 D O C U M E N T 4 0 2 D E C E M B E R 1 9 2 4
a volt is suitable as a potential). Then the gas is introduced, and meanwhile the
thread’s motion is again examined.
If the difference is constant, the experiment is done. If the difference in the mo-
tion changes randomly, we must then look for the sources of error. As such, the
principal options are: too great a velocity in the conduit, causing wind ions to form
there. Too large a potential gradient in the capacitor, causing collision ions to form.
Too weak a field in the capacitor, causing the heavy ions to pass through. (Our field
is a few thousand times greater than is necessary for capturing normal ions.) Too
high heating of the absorption vessel, whereby fluctuating voltage effects arise. All
these errors can be avoided by applying a lower field and reducing the gas flow. The
sensitivity and capacity of the electrometer are such that one can hope for the best.
If need be, I shall enlarge the dimensions of the apparatus further. The effect then
increases more than the capacity.
The apparatus is far enough along for the trials to begin on Saturday or Sunday.
If all goes well, we will have the result in a few days. Otherwise, the redesigning
must continue. I have to go to Switzerland on Dec. 26 (or Dec. 25) for about a fort-
night. Kessler is staying
here.[6]
Please forgive my long letter, and I wish you a pleasant vacation.
In great respect, yours sincerely,
A. Piccard.
402. To Gonzague de Reynold
[Berlin,] 20 December 1924
Esteemed Prof. Reynold,
Upon receipt of your detailed letter of 18 Dec. I hasten to consent to leaving to
you the decision on the remainder of the sum to be
distributed.[1]
I may surely also
speak in the name of both
Ehrenfests,[2]
as this distribution was conceived on the
basis of information that reached us jointly, and because Mrs. Ehrenfest granted me
proxy in this case (she has relieved her husband of this task). Thus nothing stands
in the way of the remittance of the remaining funds.
I have the happy feeling that we did our business as well as can be, mainly also
thanks to Mrs. Ehrenfest’s reliable connections. The fact that we are giving so
much money over here has nothing to do with my living
here.[3]
This occurred on
the basis of Dutch information, according to which a large portion of the exiled
scholars came here to Berlin and is living under far worse conditions than the por-
tion that went to Prague and to
Paris.[4]