43^ 



NA TURE 



[March lo, 1881 



Anlic Avchipelaso 



[British Expetii- j 83^° N. Floeberg Reach (Nares) - 737 F. 

 tions, 1S75-76. ( Sii^ N. Discovery Bay (Nare?) - 707 F. 



The temperature at Werkhojansk is the lowest of all 

 given here, and it murt be borne in mind that the obser- 

 vations lasted but one year, while we have more than 

 thirty-five years at Yakutsk, and eight and a half at 

 Yenisseisk. 



The mean temperatures are as follows ; — 



Though the observations were made only during one 

 year at Werkhojansk, it is probable that it would have the 

 coldest winter of all observed till now, as even at Yakutsk, 

 which is the next coldest, January and February were in 

 no single year colder than at Werkhojansk in 1S69. 

 From a comparison with the other stations of North-east 

 Siberia it is probable that here in 1S69 February was too 

 cold and December too warm. 



Now as to the reason why the winter should be colder 

 in North-east Siberia than on the North American Archi- 

 pelago farther to the north, it is to be found in the extent of 

 the continent, the distance from any sea open in winter, and 

 the prevailing calms. How important is the last reason 

 is best seen by the comparison of the December and 

 January temperatures of the last British expedition. The 

 more northerly Floeberg Beach is warmer, because more 

 exposed to winds. Now in Eastern Siberia calms prevail 

 to a large extent in winter, except near the coast. 



There is a phenomenon to be considered, which is 

 noticed everywhere in winter in high latitudes : during 

 calms with clear sky the valleys are colder than the sur- 

 rounding hills and slopes, because the cold air sinks 

 downwards and stagnates there. This is confined to the 

 night where the mid-day sun rises h'gh enough, but in 

 high latitudes during some months the mid-day heat of 

 the sun is too small and the day too short to interfere 

 much with the equilibrium of the strata of air established 

 during the night. Even in middle latitudes (4S°-5o°), 

 when calms and clear weather prevail very largely in 

 December, the valleys are regularly colder than the hills. 

 So it was felt in December, 1S79, in Central Europe. 

 What is an exception here is the rule in North-East 

 Siberia, because calms and clear sky are the rule in 

 winter ; the valleys are much colder than the hills. On 

 this account the exceedingly low temperature of Werkho- 

 jansk in winter is probably not common to the whole 

 surrounding country, and especially in the mountains 

 rising to a short distance south we may expect a much 

 higher temperature. The more we consider the conditions 

 of the winter temperature of North-East Siberia, the 

 more difficult it seems to draw isotherms. We know that 

 plains and vallejs there are colder than hills and moun- 

 tain-slopes, but how much, and what conditions are mo:t 

 favourable to that so-called interversion of temperature? 

 I consider it as highly probable that both at Yakutsk and 

 at Werkhojansk the local topographical conditions arc 

 very favourable to winter cold. This being the case, it 

 is quite natural that the latter place is colder in winter 

 than the former, being situated 5° farther to the north, 

 and yet far enough from the west to have a continental 

 climate. .\.-VVoeikcif 



* .'According to Maak. 



' Older series of Neverof(i62j-54). 



SPHVGMOGRAPHY 



'HPHE pulse has in all ages been held by physicians to 

 -'■ be a valuable aid to the diagnosis of disease, but 

 until the invention of the sphygmograph, or pulse-writer, 

 the determination of the character of the pulse was left to 

 the tutored tact of the doctor's finger, which varies much 

 in delicacy of perception in different operators, and in 

 the same practitioner at different times. At most the 

 finger, even of the most experienced, can only detect, 

 regarding the pulse, that it is soft or hard, quick or slow, 

 jerky or languid, regular or irregular ; but the finger is 

 incapable of analysing the beats, and detecting any 

 departure from the normal standard of each of their 

 component elements. The sphygmograph, which is 

 quite a modern invention, causes the pulse to write its 

 own autograph, enables us to see at a glance the peculiar 

 characters of the pulse, and to ascertain how and where 

 it differs from the healthy or normal pulse. 



Hitherto, however, the sphygmograph has been but 

 little used, for those that have been introduced are large 

 and expensive instruments, recjuiring a great amount of 

 skill and trouble to fix them on the arm and bring them 

 into action ; and for these reasons they are not available 

 for general or private practice. Hence their use has 

 almost been confined to hospital practice; but even here 



^X;^ 



they are not always available, for Dr. B. Bramwell, who 

 is a strong advocate for employing the sphygmograph, 

 relates that a patient of his was so terrified by the 

 proposal to employ the instrument that he preferred 

 leaving the hospital to allowing it to be fixed on his arm. 

 The objections to the general use of the sphygmograph do 

 not applyto the instrument recently introduced into medical 

 practice by Dr. Dudgeon, and from its portability called 

 ■' the pocket sphygmograph.'' Though this instrument is 

 so small as to cleserve the name of "pocket," it is not 

 inferior in sensitiveness to the most elaborate and compli- 

 cated of the cumbrous instruments hitherto in use, indeed 

 in some respects it is greatly superior in accuracy to any 

 that have yet appeared. Its size is 2i by 2 inches; its 

 weight only four ounces. It magnifies the movements of 

 the artery exactly fifty times. The spring that presses 

 on the artery can be regulated to press with a weight of 

 from one to five ounces, and the pressure can be altered 

 at will while the instrument is in situ. It requires no 

 vrrist-rest ; all the other sphygmographs have to be used 

 with wrist-rests of more or less complexity. It can be 

 used with equal facility whether the patient is standing, 

 sitting, or lying. With it an accurate and extremely 

 distinct tracing of the pulse can be made almost as 

 quickly as the pulse can be felt with the finger. Its 



