656 



NATURE 



[February 19, 1920 



the notation Fj for female and // for male, in 

 birds and moths, when the symbols Mm for female 

 and MM for male are so much simpler of applica- 

 tion. 



The second of the two chapters on sex, and that 

 on the chromosome theory of heredity, are almost 

 entirely new, and give a compact and useful sum- 

 mary of the outstanding facts derived from Droso- 

 phila and the hypotheses founded upon them. 

 Since nearly all this work has been done in 

 America, where students of genetics use the word 

 "sex-limited" in a sense quite different from that 

 in which it is employed in England, a few words 

 on the use of the words "sex-limited" and "sex- 

 linked " on the two side§ of the Atlantic might 

 have been a help to readers unfamiliar with the 

 subject. 



Although we have noted a few points in which 

 we think the book might have been improved, 

 we do so only because any blemishes, however 

 small, are regrettable in a book of such general 

 excellence. We still regard it, as we did in its 

 earlier editions, as one of the best introductory 

 treatises on the modern study of genetics. 



L. DONCASTEK. 



AERONAUTICS IN ITALY. 

 (i) Meteorologia Aeronantica. By Prof. Giuseppe 

 Crestani. Pp. xv-)-3i5. (Milano : Ulrico 

 Hoepli, 1919.) Price 8.50 lire. 



(2) Dizionario Internaziotiale di Aeronavigazione e 

 Costruzioni Aeronautiche. Italiano, Francese, 

 Inglese, Tedesco. By Mario Mele Dander. Pp. 

 vii + 227. (Milano: Ulrico Hoepli, 1919.) Price 

 6.50 lire. 



(3) L'Aviazione. Aeroplani, Idrovolanti, Eliche. By 

 E. Garuffa. Seconda edizione. Pp. xxiii + g55. 

 (Milano : Ulrico Hoepli, 1919.) Price 20 lire. 



(i) '"pHE introduction and development of aerial 

 1 navigation have brought into existence 

 new applications of nearly every branch of experi- 

 mental study, but perhaps none have been brought 

 into greater prominence than meteorology. The 

 safety and success of the pilot involve the most 

 careful study and observation of every element, 

 since barometric pressure, temperature, wind velo- 

 city, and cloud formation all affect the navigation 

 of the machine. Hence Prof. Crestani's book will 

 meet a real demand on the part of those who are 

 training as pilots. There is, however, no essen- 

 tial difference between aeronautical and ordinary 

 meteorology, except that more is required of the 

 former. The first part deals with instruments 

 and methods of observation. It describes the 

 princ'pal apparatus used in an observatory, and is 

 in no way limited to the special equipments rc- 

 NO. 2625, VOL. 104] 



quired for aircraft. Part ii. treats of the principal 

 aerial phenomena, including atmospheric electricity. 

 In part iii. the author deals with weather charts, 

 pressure areas, and the circulation of the atmo- 

 sphere, while part iv. is concerned with weather 

 prediction. As an introduction to ordinary 

 meteorology treated popularly, the book serves its 

 purpose quite well. Still, as we have said above, 

 something more is required by the pilot. We 

 should like to see more about the means of making 

 observations with the limited equipment that can 

 be carried on aircraft, the modifications in weather 

 prediction dependent on change of position and 

 altitude during a flight, measurements and studies 

 of solar radiation considered with reference to air- 

 ships, and so forth. There is certainly room for 

 additional treatment in regard to meteorological 

 observations which are peculiar to aeronautical 

 work. Meanwhile, the pilot must gain this know- 

 ledge by experience, and his one duty is to learn to 

 observe and interpret phenomena instinctively. 



(2) Lieut. Dander's pocket book provides for 

 pilots and aeronautical engineers a dictionary 

 similar in scope and plan to that supplied for gun- 

 nery by the " Trilingual Artillery Dictionary " re- 

 viewed in Nature of November 27 last. It pos- 

 sesses, however, several features which were 

 not contained in the subject of the previous 

 review. Thus German is included, as well as 

 English, French, and Italian, and, what is 

 also' extremely useful, anyone who is in doubt 

 as to where to find a particular word will 

 see at the end an index in which words 

 in all four languages mixed are arranged in a 

 single, strictly alphabetical sequence. This index 

 is in rather small print, but as it is scarcely likely 

 to be required up in the air this does not much 

 matter. It renders the dictionary equally useful 

 for persons of any of the nationalities which it 

 covers, but English readers would prefer that the 

 genders should have been indicated in Italian and 

 French as well as in German. Airships as well as 

 'planes are considered, and materials of construc- 

 tion, including the names of timber trees, are fully, 

 dealt with, thougli the mathematical as distinct 

 from the technical side is practically unrepre- 

 sented. There are a few examples of weird 

 English in the work, such as "three-plane," "heli- 

 coptery," "cok pit," "vestment" (for costume), 

 not to omit the American "airplane." On 

 pp. 48-49 the author evidently overlooks the possi- 

 bility of wanting to paint anything red or black or 

 even brown, but these colours are in other 

 dictionaries. 



(3) If Dr. Garuffa 's book is to be regarded as 

 representative of the present state of development 

 of aeronautical engineering in Italy, English 



