NOTES 143 



become indispensable to all those whose work brings them into contact 

 with problems of a physical character. The articles are of sufficient length 

 to be really comprehensive, and the references show that the results of very 

 recent research have been incorporated in them. The writers are without 

 exception men of recognised reputation as theoretical or experimental 

 physicists, and in most cases have an expert knowledge of the subjects on 

 which they write. The publishers have done their share of the work most 

 admirably and their enterprise deserves every possible success. 



The Institute of Physics is collaborating with the National Physical 

 Laboratory for the production of a Journal of Scientific Instruments. A 

 preliminary number has been circulated in order to ascertain the amount 

 of support such a journal is likely to obtain. No periodical of this type 

 has heretofore been published in English, although a somewhat similar 

 journal has appeared for some years in German, and in France another, 

 dealing more particularly with optical instruments, has just been started. 

 If a sufi&cient number of subscribers are forthcoming the journal will appear 

 monthly, the subscription being 30s. per annum. Each number will contain 

 thirty-two pages, and the editors ought to find little difficulty in filling these 

 with articles of first-rate importance. It will be very disappointing if the 

 support given to the Institute in this, its first, venture is inadequate, more 

 especially as a similar publication is about to be started in the United States. 



One of the features of scientific work in America is a craze for the inven- 

 tion of new units and the redefinition of old ones. A letter to Science from 

 the Blue Hill Observatory, Harvard, gives some very necessary information 

 as to the meaning of the Kelvin kilograd scale of temperature. If we follow 

 this correctly it is designed to make the coefficient of expansion of air at 

 constant pressure equal to 'ooi instead of '00366, and to this end the zero 

 of the scale is taken at the absolute zero — 273' 12° Ac (? Absolute centigrade) 

 and the " freezing-point of pure water at megabar pressure 1,000." The 

 calorie is then defined as the quantity of heat required to raise the tempera- 

 ture of I gram of pure water from 1,000 to i, 003*66 Kelvin kilograds. It 

 is claimed that this scale shortens calculations and is independent of that 

 very variable quantity the boiling-point of water. 



The Nobel Prize Address delivered by Max Planck before the Royal 

 Swedish Academy of Sciences in June 1920, and entitled The Origin and 

 Development of the Quantum Theory, has been translated by H. T. Clarke 

 and L. Silberstein and may be obtained from the Clarendon Press (Oxford, 

 price 3s. 6d. net). In twenty pages of large print it contains an historical 

 survey of the development of the theory such as could only be given by one 

 who had contributed largely to that development. In spite, however, of 

 the absence of any mathematics, the lecture will only be appreciated properly 

 by those already familiar with its subject. 



We have received Bulletins No. 16 and 17 of the National Research 

 Council of the United States. No. 16 is entitled Research Laboratories in 

 J ndustrial Establishments of the United States, and is only of interest in this 

 country as showing the enormous number of graduates in chemistry, physics, 

 and engineering who find a place in American industry. Thus the Eastman 

 Kodak Co. is returned as employing 46 chemists, physicists, and photographic 

 experts with 60 assistants ; du Pont, E. I., de Nemours & Co., 200 graduate 

 chemists and engineers, while the Western Electric Co. return their research 

 stafi as approximately 825 physicists, chemists, and engineers, and 750 

 draughtsmen, assistants, etc., their laboratory being a thirteen-story building 

 of 400,000 sq. feet floor area. Altogether 526 firms are returned as employing 

 research stafis, though, of course, many of these are small consulting firms 

 with works laboratories. Bulletin No. 17 contains an abstract of the papers 

 presented before the second annual meeting of the American Geophysical 

 Union held at Washington in April 192 1. Twenty-three papers altogether 



