On a Simple Nucleus-counter

Abstract

Improvement of the nucleus-counter of Aitken type was done to use it in routine works.The principal points of impyovement are as follows:
(1) A rubber sheet was used at the pump, just as in Wilson's cloud chamber, to prevent the leakage of air.
(2) For counting drops, a microscope was used instead of a lens. It made counting easier to all observers, and moreover we could count drops, with another eye-piece of different power of magnification, to a larger extent of the number of drops without using a dilution-pump.
(3) As a dilution-pump, Scholz's type was adopted. We could measure necessary volume of air more accurately by this pump than by Aitken's one.
(4) No leakage of air occurred through the pump in each stage of successive expansions of the same sample of air, thus it enabled us to measure neuclei-spectrums using various ratio of expansions.
(5) According to the result of investigations of F. J. Scrase, the stirring-vane was removed from this chamber.
(6) This apparatus was tested at various heights of Mt. Fuji both in summer and in winter seasons, and proved its excellent functions.