摘要:

This paper is the third and last of a series of papers on an experimental investigation on probability. Steel balls were dropped on a horizontal steel plate in which holes were bored in a regular pattern. The probability that a ball will pass through a hole without touching the plate is calculated from the known data and found to be 0.3554 ± 0.0005. The experimental value of the probability or the ratio of free passages to the total number of balls dropped is 0.35557. The agreement is very good. The numbers of runs of various lengths were calculated and compared with the actual numbers of these runs, again with good agreement. π may be calculated from the experimental value of the probability.

ISSN:1923-4287    

DOI:10.1139/cjr37a-016

出版商:NRC Research Press    

年代:1937

数据来源: NRC

摘要:

It is of advantage to the spectroscopic analyst to have a means of quickly preparing a step-weakener of any required characteristics. A method has been developed in which antimony films are deposited by thermal decomposition of the trihydride. The apparatus required is simple, and a multi-step, weakener may be made in 20 min. The films are nearly neutral below λ 4000Å. Their optical density is quite uniform, and they are sufficiently strong for all practical purposes. For high precision work, the construction of the weakener must be such that undesirable interference effects are avoided. A consideration of the theory of interference phenomena in light transmitted through thin plates suggests several possible methods of construction. Some of these have been adopted and have been found to be satisfactory in practice.

ISSN:1923-4287    

DOI:10.1139/cjr37a-017

出版商:NRC Research Press    

年代:1937

数据来源: NRC