496 



NATURE 



[(J»^ioi.i.k 6, 1923 



of the leaves when the overlyinj^ air is already satur- 

 ated. His excursion into the dynamics of travelling 

 cyclones and anticyclones forms a less fruitful but not 

 less interesting portion of his work. By an experi- 

 mental arrangement of the ingenious kind that might 

 be expected from him, he sought to demonstrate the 

 flow of air into a region of low pressure. Inside, and 

 near the lower end of, a vertical metal tube, three gas 

 jets were lit and the lines of flow of air into the up- 

 draught in the tube were then studied. The spiral 

 motion was represented as being due to non-uniform 

 distribution of velocity in the horizontal plane through 

 the lower end of the tube. His theory was that anti- 

 cyclonic areas supplied descending and therefore heated 

 air to cyclonic areas, and also supplied " the cyclone 

 with part of the tangential force necessary for produc- 

 ing the spiral circulation so well known in cyclones." 

 Further, that — 



" the upper winds, circling from the anticyclones, and 

 to the cyclones, by moving more quickly, and by 

 moving at an angle across the lower air, tend to prevent 

 the latter rising, even although it be the lighter. The 

 effect of this ... is to drive the hot moist air lying 

 near the earth's surface to the circumference of the 

 anticyclone where it is picked up by the cyclone, and 

 as the spirally moving cyclonic winds also tend to 

 prevent the lower air rising, the hot moist air is swept 

 into the front of the low-pressure area . . . and it is 

 drawn into the centre of the depression and . . . forms 

 the core of the cyclone." 



Sir Napier Shaw has pointed out, however, that the 

 difficulty lies in deciding whether or how far any ex- 

 periment such as Aitken's really reproduces the natural 

 conditions on the larger scale. To begin with, that 

 portion of the atmosphere within a cyclonic area has 

 no resemblance to a vertical column the height of 

 which is a dozen times its diameter ; its axis is most 

 probably not vertical ; it is not provided with a con- 

 stant heat supply at its base ; its core is almost 

 certainly not a mass of warm moist air ; and the distri- 

 bution of temperature is not symmetrical about its 

 " centre." Lastly, the whole system moves in a field 

 of force the characteristics of which are not altogether 

 simple. Thus, although Aitken's experiment forms an 

 ingenious illustration of eddy motion in a fluid, his 

 theory of cyclonic motion has not done much to advance 

 the subject, except that it has stirred up the interest of 

 others in the matter. Recent years have brought 

 additional information, but the end is not yet ; nor 

 will that be reached without more extensive exploration 

 and study of the first six or eight kilometres of the 

 atmosphere lying over and within cyclonic areas. This, 

 perhaps, is the greatest need of the meteorology of 

 to-day. 



Notice must be taken of the admirable sketch of 

 NO. 2814, VOL. T 12] 



Aitken's work, drawn up by the late Dr. C. G. Kn<it! 

 He shows Aitkcn as a typical example of the priv;i- 

 scientific inquirer — a class to whom British scieti 

 owes much. With ample private means, he pursti- 

 his inquiries in his own time and in his own way, hapj 

 in freedom from those distractions which seem 1: 

 separable from the o<:cupation of official position. I ' 

 did his work because he loved it ; he sought for t i 

 truth because it was " something true and good ! 

 ever, not the mere outcome of craft or expediency.' 



Dr. Knott's editorial work has been done with ca: 

 and discrimination. But a melancholy interest attaches 

 to it, for the date of his imprimatur shows it to have 

 been the last piece of work in a long and useful life. 



A. r M 



A Zoological Tribute. 



Bydragen tot de Dierkunde. Uilgegeven door iiet 

 Koninklijk Zoologisch (Jenootschap Natura Artis 

 Magistra te Amsterdam. Feestnummer uitgegeven hij 

 gelegenheid van den "josten geboortedag van Dr. 

 Max Weber, oud Hoogleeraar in de Zoologie aan 

 de gemeente Universiteit te Amsterdam. Pp. 342. 

 (Leyden : J. Brill, 1922.) 25 guilders (2/. is. Sd.). 



TOWARDS the end of last year the Royal Zoo- 

 logical Society Natura Artis Magistra of Am- 

 sterdam issued the twenty-.second number of its 

 publication, " Bydragen tot de Dierkunde " (Con- 

 tributions to 2^ology), on the occasion of the seventieth 

 birthday of Prof. Max Weber. To this large volume 

 no less than forty-four zoologists have contributed 

 papers on various subjects, and all thus unite, each 

 in his own way, " to weave a small leaflet into the 

 wreath which his adorers, friends, and pupils offer 

 him on this festivity." 



As the table of contents itself includes a considerable 

 number of papers, it is easy to understand that we 

 cannot possibly give a summary of each contribution 

 in particular, for such an account would exceed the 

 limits of the space available in Nature. We must 

 therefore content ourselves with mentioning those of 

 special interest, first to the distinguished zoologist to 

 whom the collection is dedicated, and next from the 

 point of view of science. 



No more sincere admiration of Weber's investiga- 

 tions of the fauna of the Dutch East Indies, and 

 his endeavours to establish scientific collaboration 

 between the colonies and the motherland, can be 

 expressed than is done by Koningsberger in his partly 

 historical, partly modem, consideration of biological 

 research work in Dutch Asiatic colonies. The zoo- 

 geographical problems of this archipelago, which have 



