Feb. 1 8, 1886] 



NA TURE 



\19- 



It can be proved in many ways that the lumbar curve of the 

 spine is more marked in the human female than in the male. 

 I'he methods adopted for the ehicidation of this point were : (l) 

 tracings of mesial sections of the frozen spines of the two sexes ; 

 (2) Measurements of the anterior and posterior surface of the 

 lumbar region ; and (3) measurements of the individualkimbar 

 vertebra. 



The difference between the indices of the vertebras of the two 

 sexes are not confined to Europeans, but are also observed in 

 four of the five lower races examined, as will be seen from the 

 f:illowing table : — 



It can be shown that the indices of the lumbar vertebra of a 

 given European spine are in strict accordance \A'ith the degree 

 of lumbar curve. But, whilst this is the case, the difl^erence 

 between the anterior and posterior vertical diameters of the 

 vertebral bodies is so slight (as Weber has observed) that it can 

 have little effect in producing the luinbar curve. The form- 

 adaptation of the vertebral bodies must, therefore, be regarded 

 as the consequence, and not as a cause, of tlie curve : at the same 

 time it cannot be due to an immediate and mechanical influence 

 operating upon the vertebral bodies during the life of the indi- 

 vidual. If it were so, the same characters would be present in 

 the lumbar vertebras of the low races, and even of the anthro- 

 poid. It is an hereditary condition. 



The European, who leads a life which rarely necessitates his 

 forsaking the erect attitude except as an intermittent occurrence, 

 and then for short periods, has sacrificed in tlie lumbar part of 

 tlie vertebral coIumn7?e-.»-/^z7//)' for stability. It is evident that 

 the deeper the bodies of the vertebrae grow in front, the more 

 permanent, stable, and fixed the lumbar curve will become, and 

 the more restricted will be the power of forward-bending in this 

 region of the spine. The savage, in whose life agility and sup- 

 pleness of body are of so great an account, who pursues game 

 in a prone position, and climbs trees for fruit, &c., preserves the 

 anthropoid condition of vertebra;, and in consequence possesses 

 a superior flexibility of the lumbar part of the spine. 



SNOW-COVERING AND THE WEATHER 

 'TjR. WOEIKOF, who is one of the meteorologists of the 

 modern school, has long entertained a deep conviction 

 that meteorology ought not to limit itself to a mere observation 



of those few instruments which for nearly fifty years have con- 

 stituted the plant of meteorological Observatories. In the 

 development of its general laws and the application of them to 

 forecasts of weather, it must widen the circle of its observations, 

 and take into account those factors upon which weather and 

 climate depend in each given locality. For the past fifteen 

 years he has devoted his time to the study of local climates and 

 their dependence upon local causes, such as the local deflections 

 of the paths of cyclones and anticyclones ; the proximity of 

 seas, steppes, marshes, and forests, and the local heating and 

 cooling of the ground. His chief work, published in Russian, 

 entitled "The Climates of the Globe," is most valuable, on. 

 account of the wide Knowledge it evinces of the various circum- 

 stances on which climate depends, especially with regard to the 

 immense plains of Russia. 



The influence of the snow on climate, of its depth and con- 

 sistency, the time of its first appearance and disappearance, the 

 evaporation from its surface, the purification of air when it has 

 fallen, and a variety of minor circumstances, the importance of 

 which has been insisted on by Dr. Woeikof since 1872, are all 

 referred to. Unhappily, observations on snow are veiy few and 

 imperfect, and in a paper recently read before the Russian 

 Geographical Society, and now printed in its JMcnioirs (xv. 2), 

 he returns to the subject, illustrating the importance of such 

 observations by a few well-chosen examples. 



The year 1S77 was a striking instance of how the absence of 

 snow was accompanied by a far less notable lowering of tempe- 

 rature during the prevalence of anticyclones than would have 

 been the case had the soil been covered with snow. In 1877 

 there was no snow in Eastern Russia until Christmas, and in 

 November and December the anticyclones occurred, accom- 

 panied by no wind, or only by feeble breezes. Quite bright 

 weather lasted in December for more than ten days ; and still in 

 the region which remained uncovered with snow no great cold 

 was experienced as usually happens in such circumstances : the 

 minima were 8° to 9° above their average values. The same 

 conditions were noticed during the winters of 1S79- 80 and 1S81- 

 82, in West Europe, as shown by Dr. Billwiller in the Zeitschrift 

 jiir Meteorologii for 1 882. 



In Dr. Woeikof 's opinion the relatively high mean tempera- 

 ture of November, as compared with March, in South-East 

 Russia and the Kirghiz Steppe may be explained by the circum- 

 stance that in these localities the soil usually is not covered with 

 snow in November ; and thus, not being separated from the air 

 by the snow, which is a bad conductor of heat, it rather con- 

 tributes to maintain a higher temperature in the air resting on it. 

 On the other hand, towards the end of winter the surface is 

 much cooled and exercises a refrigerating influence on tlie air. 

 Examples from the United States adduced by M. AVoeikof 

 seem also to confirm this view. 



Th-i refrigerating influence of a thick covering of snow in the 

 spring and the influence it exercises in retarding the arrival of 

 wann weather is so obvious that it need not be insisted on, A 

 paper was written by M. Woeikof, in 1872, on this sub- 

 ject ; and the very interesting illustrations he has adduced to 

 show the refrigerating influence of a snow-covering during years 

 when snow was abundant, are very striking. He has since re- 

 turned to this subject in his " Climates of the Globe," and in 

 the paper we mention ; and we may consider it quite established 

 that it is precisely to this agency that the relative coolness of 

 the spring months in Russia and Siberia is due. Mnreover, it 

 may be considered as certain that when the snow-covering has 

 been thick, and especially when the snow has a harder con- 

 sistency, the aiTival of warm weather will come on late in the 

 spring. 



Another result which Dr. Woeikof has established relates to 

 the commencement of first durable frosts. As long as there is 

 no snow, or little, he argues that frosts may begin, but they 

 will not be durable, and the temperature may rise above the 

 freezing-point ; but it is the snow-covering, although not very 

 thick, which gives durability to cold weather. It is easy to 

 foresee how important it becomes, in forecasting the weather, 

 to know, both in spring and autumn, if there are, to the north 

 and east of any region, broad spaces covered wiih snow. 



It is useless to insist upon the importance of an exact know- 

 ledge of the depth and consistency of the snow for forecasts in 

 the interests of navigation, especially in countries like Russia, 

 where navigation on so many rivers is carried on only at liigh 

 water. Several interesting illustrations of this influence are 

 given by the author. In view of these important results, it is. 



