184 



NA rUKE 



Kc. 



land situations. As on similar occasions, the inflaence of the 

 sea in arresting the fall of temperature was strikingly seen. 

 Thus the minimum temperatures on the 21st were 3i°'7 at Port- 

 patrick, S°'3 at Drumlanrig Castle on the Nith, i°'0 at Stoho 

 Castle and Thirlestane Castle, i:°'7 at Mihie Gradennear Cold- 

 stream, and I7°7 at Eyemouth on the East Coast. At Douglas 

 Castle and Thirlestane Castle the unprotected thermometer fell 

 to -6°'0. 



Mr. H. S. Eaton has rendered a great service to meteorology 

 by a paper on the average height of the barometer in London, 

 which has just appeared in tlie yotinial of the Meteorological 

 .Society for October. The great value of the paper consists not 

 so much in the long period of 100 years for which the monthly 

 averages of each year are given, as in this, combined \\ ith a care- 

 ful and laborious elimination of instrumental errors and errors 

 arising from breaks of one or more days in the observations of 

 the months. The series is sufficiently extended as to entitle it 

 to be considered one of the most valuable we possess in dealing 

 with questions of secular meteorological variations. The mean 

 atmospheric pressure at 32' and sea-level for London is 29'952 

 inclies, the mean monthly maximum 29'996 inches occurring in 

 Jime, and the minimum 29 "900 inches in November, the mean 

 for October being nearly as low, viz., 29*909 inches. In a dis- 

 cussion which followed the reading of the paper Mr. Strachan 

 remarked that even another 100 years' observations would not 

 alter the positions of these points of the London curve — a remark 

 no doubt quite true for London. On advancing however to the 

 south-west the means for June and July approach toward 5 equality, 

 and ultimately the July mean becomes the larger as we advance 

 into the region of high pressure which occupies the Atlantic to the 

 south-west during this month. On the other hand, as we pro- 

 ceed northward, the means for May and June approach towards 

 equality till about the south of Scotland the mean for May 

 becomes the maximum for the year, and the further north the more 

 decidedly is May the maximum, till in Iceland it exceeds the 

 mean of any other month by the tenth of an inch. Attention 

 was drawn to the dips in the curve of pressure for April and July. 

 These in all probability are permanent features in the London 

 curve of pressure for March-April and July when drawn from a 

 long average, since the former is connected with the east winds 

 of spring and the latter with the great summer barometric de- 

 pression which falls to the lowest point in July in the interior of 

 the Europeo-Asiatic continent. 



In the same number Mr. Marriott gives a brief risumc of 

 three years' observations made by Mr. F. E. Cobb at Stanley, in 

 the Falkland Islands, which, from the geographical position of 

 the place, possess some interest. The results show a mean 

 annual pressure of 29*604 inches, the maximum occurring in 

 winter, and the minimum in summer. A singular feature of the 

 monthly means is their comparative steadiness from year to year, 

 the highest being 29-819 inches for August 1876, and the lowest 

 29-342 inches for February of the same year. The difference of 

 these two extremes is only 0*477 inch. It would be difficult to 

 select from Mr. Eaton's 100 years mean pressures for London 

 any consecutive three years which woidd show so small a varia- 

 tion between their two extreme monthly means as do these Falk- 

 land Islands' observations. The prominent features of pressure 

 in those islands would appear to be its variability, the coi, slant 

 recurrence of rapid changes, and the comparative absence of j.ro- 

 tracted periods of very low, but especially very high pressures — 

 occasioned in all likelihood by there being no great mass of land 

 in that quarter of the globe. A like equableness from year to 

 year characterises the temperature and rainfall of the climate. 

 The rainfall is surprisingly jmall, amounting only to twenty 

 inches in the year ; but the falls, though not heavy, are frequent, 

 there being 236 rainy days in the year. The lowest mean 

 temperature of any of the thirty-six months was 35°'4, and the 

 highest 52° "6. The climate is eminently a dripping one, and 

 when the range of its temperature is taken into consideration, 

 and its high winds, it is one of the most disagreeable climates of 

 the globe. 



GEOLOGICAL NOTES 

 Naini Tal Landslip.— In Nature, vol. xxii. p. 505, 

 attention was directed to landslips in connection vvi h the 

 catastrophe at Naini Tal on September 18. We have just 

 received part 4 of vol. xiii. of the Records gf the Geological 

 Survey of India, containing a paper by Mr. R. D. Oldham, of 



the staff of that Survey, who was deputed to examine and report 

 on the landslip to the Director. From this paper and a note 

 appended to it by Mr. Medlicott, it appears that we were in error 

 in supposing Naini Tal to stand upon Tertiary rocks. It lies 

 just to the north of the younger form itions, and is situated upon 

 "more or less imperfectly-cleaved clay slates." These rocks 

 are subject to a decomposition which penetrates deep into their 

 mass, and it would seem to have been the cover of loose, de- 

 composed detritus which, thoroughly saturated with water from 

 the heavy rains, slid down the hill, and gave rise to the 

 catastrophe. 



The "Challenger" Work. —Steady progress is being 

 made in the investigation of the deep-sea deposits dredged up 

 by the Challenger Expedition. M. Kenard has established him- 

 self at Edinburgh, where, in concert with Mr. J. Murray, he is 

 busily engaged in subjecting the various dredgings to chemical 

 and mici oscopic an.ilysis. In the first volume, devoted to an 

 account of the bottom of the ocean, will be gathered together 

 the facts amassed during this laborious study. It will avoid all 

 speculation, but will contain such a body of data for the expli- 

 cation of the sedimentation and chemistry of the ocean abysses as 

 has never before been available. In a subsequent volume the 

 authors will develop the views to which their prolonged and 

 minute investigations have led them. No part of the work of 

 the Challenger promises to possess a profounder interest in 

 geology. 



Geologic.\i, Survey of Belgium. — The dual organisation 

 for the Geological Map of Belgium is likely to lead to some 

 curious reduplications and complications. Besides the staff under 

 the direction of M. Dupont, there are other geologists inde- 

 pendently at work under the Ministry of the Interior who are 

 determined to lose no time in bringing out sheet after sheet of 

 the geological map as surveyed by them. In particular the 

 Baron O. Van Ertborn and M. Paul Cogels have been eminently 

 energetic. The Baron made a convention with the Ministry 

 towards the end of last year to complete six sheets with their 

 explanatory texts before June i of the present year. He 

 has been able to keep his engairement except as regards the 

 Lubbeek sheet, for which he obtained a delay until the close of 

 this year. We have just received the Boisschot and d'Aerschot 

 sheets. Meanwhile M. Dupont makes no sign. Specimens of 

 his map were seen at the Paris Exhibition in 1S78, and also at 

 the Dublin meeting of the British A-^sociation last year. But 

 so far as we are aware, nothing has yet been issued. The 

 Director is understood to be resolved to make his map the most 

 perfect geological map that has ever been published. It is being 

 chromolithographed at Leipzig. Considerable interest is natu- 

 rally felt among geologists to see the fir.-t completed specimens 

 of this long-expected work. We are curious also to know what 

 will happen wUen the Oflicial Survey and the free-lances meet 

 on the same ground. Will the Government publish two different 

 geological maps ? The position reminds us of that which roused 

 the activity of the Congress of the United States a few years ago, 

 when it was discovered that the same Territory in the far West 

 was sometimes independently surveyed by two or three different 

 organisations, all paid out of the public purse. Only in Bel- 

 gium things are wirse, for the country is small, and the certainty 

 of reduplication must have been foreseen from the beginning. 



GEOGRAPHICAL NOTES 



At the meeting of the French Geographical Society on 

 November 19, M. Henri Duveyrier read an important memoran- 

 dum which he had drawn up on the subject of the sources of the 

 Niger. After going carefully into the question of Major Laing's 

 prior discovery and various matters relating to the hydrographic 

 system of the Niger basin, he thinks it very doubtful if any other 

 stream will ever be discovered having a right to be deemed the 

 chief source of the river, than the Tembi-Kundu -visited by 

 MM Zvveifel and Moustier. M. Duveyrier's remarks will no 

 doubt be published in an early number of the French Geogra- 

 phical Society's Bulletin, and it may be hoped that it will be 

 illustrated by a large scale map. At the annual meeting of the 

 Society last Friday, M. Maunoir read his usual report on the work 

 of the Society and the progress of geographical knowledge. It was 

 announced that the Society had now about 21CO members, being 

 an increase of about 100 in the year. 



Heft 3 of vol. ii. of the Mittheilungen of the German African 

 Society contains a brief report of the work of the year. The 



