Jan. I, 1880] 



NATURE 



have to be made in the application of Howard's ter- 

 minology, and no terms will have either to be coined or 

 to be introduced from other systems of classification into 

 that of Howard, with the exception of the affix " fracto," 

 and the affix "mammato " (or one equivalent to it). We 

 have thought it desirable to give illustrations of the types 

 of cloud to be distinguished by these last names. In the 

 first sketch "cumulus" is shown with " fracto-cumulus '' ; 

 in the second "stratus" with " fracto-stratus " ; in the 

 third the characteristic base of " mammato-cumulus " ; 

 and in the fourth that of " mammato-cirrus." 



We arc not without hopes that Prof. Poey will be in- 

 duced to give his aid to proposals of moderate reform 

 in the direction above indicated. We are convinced that 

 he will find it easier to modify, by limitations and ex- 

 pansions, a long existing terminology, wherever the terms 



are essentially truthful and expressive, than to sweep it 

 away and introduce another in its place. 



To return to the book under notice. " How to classify 

 the Clouds " would be a more descriptive title than that 

 which it possesses. However, the reader who wishes 

 to learn the art of cloud observation, with the view of 

 learning to forecast the weather, will obtain valuable in- 

 formation from the descriptions which the author founds 

 upon his own observations, as well as from those which he 

 quotes from other observers, e.g. the exquisitely truthful 

 description of cirrus quoted from Bravais (pp. 64 and 65). 

 Some of the remarks on the azimuthal rotation of the 

 clouds in Havanna, and on other phenomena,' are well 

 worthy of the attention of meteorologists. Here, e.g. is 

 an observation, which, taken in conjunction with the 

 inclination of the axe; of cyclones and anti-cyclones in- 



dicated by cloud-observations in Europe, and also with 

 the recent conclusions of Prof. Loomis as to the sequence 

 of winds at the American mountain observatories, may 

 point to an important general law ; "dans le plus grand 

 nombre de cas, le vent anticipe sur les fracto-cumulus, 

 ceux-ci sur les cirro-cumulus, et ces dcrniers sur les cirrus, 

 e'est-a-dire de bas en haut, au lieu d'etre de haut en bas. 

 Ce fait parait contredire l'hypoth&se que les courants 

 superieurs de'terminent, de proche en proche, le passage, 

 sous le meme parallele, des courants inferieurs jusqu'aux 

 vents de surface" (p. 127). 



One who writes on a generally neglected subject, to 

 which he has himself devoted much attention, is often 

 tempted to accept too readily as grist anything that comes 

 to his mill, and Prof. Poey is not altogether free from 

 this tendency, especially in those parts of his works in 

 which he launches out into very questionable hypotheses 



both on the theory of winds, and on the action of heat and 

 of electricity upon the clouds. Stiil more to be regretted is 

 a certain looseness, not so much of language as of con- 

 ception, which occasionally leads him to make some 

 surprising statements, as well as to employ inaccurate 

 expressions. 



He usually speaks of the water-clouds as composed of 

 aqueous vesicles, sometimes of vesicular vapour. In one 

 passage, speaking of frozen clouds, he talks of the " vesi- 

 cular vapour passing from the state of particles of ice to 

 those of snow " (p. 77). 



A protest is necessary against his often repeated defini- 

 tion of cumulus as a "cloud of the horizon." He says 

 (p. 23), "Nous pouvons assurer que, sous toutes les 

 latitudes du globe, les cumulus sont specifiquement des 

 nuages d'e/e, dtjour, et de ^horizon." And again (p. 104), 

 "lis demeurent toujour; confine's a 1' horizon, et netravers- 



