512 



NA TURE 



[April 3, 1902 



observation of December 3, the relative humidity of the air was 

 75 per cent., the wind calm, and (he barometer, corrected to 

 32 and sea-level, 30284 inches. On January 7, relative 

 humidity was 765 per cent., wind faint : barometer 30499 

 inches. The altitude of this station is 480 feet; lat. 54° N., 

 long, r.36 W. G. Paul. 



Corporation 01)servatory, Harrogate, March 24. 



The sun pillar described by your correspondents was very 

 well seen from the railway between Netley (5.40) and South- 

 ampton (6 p.m.), and lasted, I think, more than half an hour. 

 It was visible before and after sunset. The upper air at the 

 time was remarkably calm ; the morning had been foggy, and 

 the morning of March 7 was also foggy on the ground. Obser- 

 vation of the upper clouds on the morning of the 6th, and at 

 the time of the phenomenon, showed an extremely slow move- 

 ment from the north-west, barely noticeable between telegraph 

 wires overhead. At 9 a.m. on the 7th cirrus was moving very 

 slowly from about north, and at noon from northwest. 



R. Russell. 



Condercum, Alum Chine, Bournemouth, March 24. 



The accounts of this rather rare phenomenon (as it seems to 

 be) come (so far) only from the south-west of England. It is, 

 therefore, worth while adding the following as seen at Oxford 

 by myself and friends : — 



March 6, 6.18 p.m. — A vertical pillar of flame-coloured light, 

 springing ]irobably from the sun below the horizon, quite 

 parallel sided, about ''<,' wide and 6° high, careful measurements, 

 perfectly steady for the 10 minutes that we were able to look 

 that way. We thought there was a condensation of Hght, as of 

 a faint mock sun, about 4- above the horizon. It was fading 

 ofT downwards appreciably at the last moment. 



Littlemore, Oxford. W. J. Herschel. 



\\' the phenomenon of so-called "sun pillars" can only 

 obtain when the atmosphere is " quite free from convection 

 currents . . . (which it seldom is) " [see Nature, March 20], 

 is it not reasonable to suspect that the thing seen on March 6 

 was tiot such an atmospherical phenomenon? since it was 

 viewed east and west from Brighton to the Cornish coast and 

 northwards to High Barnet and Carmarthen Bay, so far as has 

 been already ascertained. 



If the barometrical and thermometrical readings, wind 

 velocities and directions over this wide area on the 5th, 6th 

 and 7th inst. could be obtained, an examination of these would 

 go far to settle the question. Catherine O. Stevens. 



Bradfield, Berks, March 31. 



Sounds Associated with Low Temperatures. 

 The whistling or squeaking of snow under foot at low tem- 

 peratures is a familiar phenomenon to residents in such climates 

 as that of Canada. The sound is in strong contrast to the 

 crunching of snow at the freezing point. 



I suspect that "walking about the sheds" in the letter 

 quoted by Sir Wm. I'reece (p. 487) means walking over snow- 

 covered ground between the sheds. J. D. Everett. 



II Leopold Road, Ealing, March 29. 



I have, I think, frequently heard the sounds mentioned in 

 the letter sent to you by Sir William Preece ; but if the sounds 

 I mean are the same as those there described they arc not 

 necessarily associated with low temperatures, though they 

 would be more likely to be noticed when the ground is frozen. 

 The sounds to which I refer are to be heard near palings or 

 sheds made, as they frequently are, with overlapping boards. 

 The explanation I have always supposed to be as follows : — If 

 the ground is sharply struck, with the boot for instance, the 

 sound thus made will be reflected back by the ends of the 

 boards ; as each of these ends is further from the listener than 

 its neighbour, the echoes will come back at intervals depend- 

 ing on the distance of the observer from the paling and on the 

 width of the boards ; if the boards are of equal width, the echoes 

 will come back with nearly equal intervals between them, thus 

 producing a musical note. If the ground is frozen, the sharp 

 sounds necessary will be produced when walking by one's boot 



NO. 1692, VOL. 65] 



striking the ground ; but the same sounds may be produced in 

 dry weather and especially when walking on gravel. I have 

 often observed the musical note, but never where such an ex- 

 planation would not be possible. Wooden palings are not, how- 

 ever, necessary ; I have heard the same thing when walking past 

 iron palings, more particularly, as is to be expected, when the 

 uprights have a square section. Charles J. P. C.we. 



Binsted, Cambridge, March 31. 



CENTRAL AND SOUTH AMERICA} 



pENTRAL AMERICA and the West Indies are 

 ^ attfacting so much attention at present that a 

 comprehensive description of them is of especial value 

 to all who are watching the growth of political power in 

 the New World. Hence we may welcome Mr. Keane's 

 work, which, inter alia, treats of their history, physical 

 geography, climate, tlora, fauna, ethnology and mdustries, 

 as well as of their financial and commercial statistics. The 

 volume, although purporting to be a " new issue," might 

 well claim to have no relation to the old one, edited, a 

 quarter of a century ago, by the well-known naturalist 

 H. W. Bates ; for the knowledge of the region which 

 has accumulated during the interval has been largely 

 utilised, although not brought up to date in some important 

 respects. Besides ten carefully executed maps, not 

 overloaded and confused by unimportant names, the 

 work contains numerous illustrations. 



Mr. Keane opens his subject with a comprehensive 

 chapter on the physical and biographical relations of 

 the countries under consideration. " The present Central 

 AiTierican mainland, like the Southern continent, formed, 

 originally, a vast insular region, which was gradually 

 consolidated in Tertiary and later times. It constituted 

 a great archipelago, which stretched, for about 770 miles, 

 in a south-easterly direction from Tehuantepec to 

 Panama, and presented certain analogies to the West 

 Indian insular world, with which it is in fact connected 

 by at least two chains of islets, reefs, and partly or wholly 

 submerged marine banks. ... It is difficult to realise 

 the fact that the 'American Mediterranean,' as the 

 Gulf of Mexico and Caribbean Sea are often called, has 

 a circuit from Cape Sable round to the Bahamas of no 

 less than 12,000 miles. . . . The volume of water the 

 Gulf Stream) rejoining the equatorial current north of 

 Florida strait, though relatively small, forms none the 

 less a liquid mass about fifty-five miles wide and 450 

 fathoms deep moving at the rate of from two to six miles 

 an hour, and is thus equivalent to as many as 300,000 

 rivers as copious as the Mississippi." It may be re- 

 marked that Maury is contented with giving the flow of 

 the (Uilf Stream through this strait as 1000 times the 

 volume of the mighty river mentioned. 



Mr. Keane discusses at length the ethno-gcographical 

 relations of the almost numberless tribes which have 

 made the lands bordering the Gulf of Mexico and 

 Caribbean Sea such an interesting study, and he con- 

 cedes to the Toltec, Aztec and Maya peoples a high 

 degree of civilisation. Most writers do the same, as they 

 let their imagination revel in the romantic accounts of 

 the conquest of Mexico and the descriptions of the ruins 

 found from New Mexico to Panama ; but it may be 

 doubted if any of the tribes of Indians who occupied that 

 region ever reached a higher grade than the " Upper 

 Status of Barbarism " so admirably defined by Lewis H. 

 Morgan in his ".-Xncient Society.'' 



As to the Carib race, the cradle of which Mr. Keane 

 rightly fixes in the heart of South America, they wandered 

 north to the shores of the Caribbean Sea, to which they 

 gave their name, and which recognised, throughout its 



1 St.inford's " Compendium of Geography and I'r.ivcl ' (new i.ssue). 

 " Ccnlr.ll and South America." Vol ii. Central .\merica .-ind We.sl Indies. 

 By A. H. Ke.ine. F.R.G.S. Edited by .Sir Clements .Markham, K.C.B., 

 F.R.S. Pp. xxiv-f <q6. (London: E. Stanford.) Price 151. 



