June i8, 1896] 



NA TURE 



151 



as the pioneer worker in the bacteriological method for the 

 examination of drinking-water involving the useof solid culture 

 material, viz. gelatine. Frank Scudder. 



Kllerslie, .-Viderley Edge, June 5. 



A Prognostic of Thunder. 



As the thunderstorm .season has no« sei in, may I call the 

 attention of weather observers to what seoiiis to me an almost 

 infallible prognostic of thunder, which was described in a letter 

 in Natire of July 5, 188S. 



It consists in the formation of a small ^M\x^oi parallel streaks 

 of cloud, seldom more than three or four in number, definite in 

 form, and limited in extent and duration, appearing either as 

 white streaks on the blue, or more rarely as darker streaks 

 against nimbus or cumulonimbus. 



I have very rarely seen these " parallel bars," as Lhave come 

 to call them, without their being followed by thunder within 

 twenty-four hours. 



As the v.alue of the prognostic .seems to depend on the definite- 

 ness, small magnitude, and short duration of the " bars " (since 

 one may sometimes see a large portion of the sky covered with 

 rippling clouds which are followed onlyljy rain without thunder, 

 or not even by rain), their connection with thunderstorms seems 

 to be explicable by the view that they are " interfret clouds " of 

 very limited extent, indicating the superposition of atmospheric 

 strata of very unequal temperature or humidity, with a restless- 

 ness which shows itself in local and temporary irruptions from 

 one stratum into the other ; an irregular condition very likely to 

 be associated with electrical disturbance. 



I may add that these "bars" are very readily detected after 

 being once seen, and very easily noted ; and they deserve, I 

 think, more attention from meteorologists than they have 

 received. B. Woodd-Smith. 



Hampstead Heath, N.W., June 10. 



Tufted Hair. 



I H.AVE had, within the past few days, my first opportunity of 

 examining closely the living head and hair of the African Negro, 

 on several " Kru boys" from the West Coast. Their hair, 

 which was cut moderately short, presented the usual appearance 

 of a congeries of tufts arranged in a more or less linear manner, 

 hut when closely investigated it was found to be uniformly dis- 

 tributed over the scalp — each cork-screw tuft, resulting from 

 the separate hairs on araall adjacent areas, intertwisting together 

 and forming a silky compressed curl. In New Guinea I 

 investigated the manner of growth of the hair on a large number 

 of natives from widely distant regions, on many of whom the 

 body was also covered >vith, to all appearance, little distinct 

 sjjirals. On close scrutiny, and with a little trouble, these 

 "cork-screws," both on head and body, could be perfectly 

 uncurled and separated out into indi\idual hairs growing from 

 roots as nearly as possible equidistant from a central hair, round 

 which the others coiled themselves, each hair being in fact a 

 twining-plant-like structure, laying hold of a neighbouring hair 

 as a supporting stake. Both on body and head the hair follicles 

 were evenly distributed. These facts, as regards the African, 

 are already quite well known from the investigations of Prof. 

 \'irchow and others ; but it may not be without interest if I 

 record, after this opportunity of comparing the Melanesian with 

 the Negro, that the growth of their hair in both races is identical. 



The -Museums, Liverpool, June 14. Hexry O. Forbes. 



LORD KELVIN. 



A S these words are beitig printed, the Jubilee of Lord 

 -'*- Kelvin's professorship is beinj,' celebrated in the 

 most enthusiastic and magnificent manner at Glasgow. 

 Delegates from all parts of the world are present, and 

 among them are many of the most eminent represent- 

 atives of science at home and abroad. From Paris to 

 Moscow, Canada to Mexico, India to .Australia, the whole 

 civilised world unites in congratulating Lord Kelvin on 

 the great work for science and the good of his fellow men 

 which he has achieved, and in offering good wishes that 

 be may have health and strength for the contmuance of 

 his glorious career. Though for fifty years he has been 



NO. 1390, VOL. 54] 



Professor of Natural Philosophy at Glasgow, has seen 

 pass through his classes several generations of students, 

 has been one of the greatest leaders in what has been 

 pre-eminently a century of scientific discovery and ad- 

 \ancement, has worked as few men can work, and withal 

 has taken the keenest interest in all that ought to interest 

 the true citizen of a great country, yet is his eye not dim, 

 nor his natural force abated. It is the hope of all his 

 friends, and of all the great army of scientific workers, 

 who now are unanimous in doing him honour, that he 

 may have before him many long years of happy and 

 successful work. 



Lord Kelvin, though born in Ireland in 1824, began 

 his connection with Scotland and with the University of 

 Glasgow at a very early age. His father, Professor 

 James Thomson, still remembered by many alumni of 

 Glasgow as a remarkably skilled and successful teacher, 

 was appointed to the chair of Mathematics m 1832, so 

 that when only eight years of age, William Thomson began 

 his residence at the University of Glasgow. Only two or 

 three years later he began to attend University classes, 

 and soon attracted attention by a brilliance of intellect 

 very remarkable in one so young. His proficiency in 

 mathematics and natural philosophy was very great, but 

 other studies were by no means neglected, and, under the 

 careful supervision of his father, he received a thoroughly 

 all-round and complete education. It may be mentioned 

 here, that of the importance of giving its due place to 

 science in any good scheme of liberal education, no one 

 could be more convinced than Lord Kelvin, but that no 

 one values more highly than he does the Old Humanities, 

 and the importance of a sound logical and linguistic 

 training. 



While he was yet a boy, bis interest was keenly excited 

 by such subjects as the Figure of the Earth and Fourier's 

 Theory of the Flow of Heat. On the first he wrote a 

 University prize essay, and, on the latter, a series of 

 papers in which he successfully defended Fourier's 

 researches from a charge of unsoundness which had 

 been brought against them, through some strange mis- 

 conception, by a very competent writer who had gradu- 

 ated a few years before with the utmost mathematical 

 distinction. It is worth relating, as indicating the promise 

 and power of the youthful natural philosoper, that when 

 only fourteen or fifteen years of age he read Fourier's 

 great treatise through in the intervals of travelling about, 

 during a fortnight's visit to Germany. That he did so to 

 some purpose is shown by the papers in defence, expla- 

 nation, and extension of Fourier's results, which soon 

 after flowed from his pen. 



There can be no question that, like niany^other eminent 

 physical mathematicians, Lord Kelvin has been inspired 

 and directed by his early study of Fourier and the other 

 great French mathematical writers of the end of the 

 eighteenth and the beginning of the present century. 

 But he has always fully and gratefully acknowledged the 

 helpful and interest-exciting influence of some of his old 

 teachers at the University of (Glasgow. To mention only 

 one, Dr. J. P. Nichol, formerly Professor of Astronomy 

 in the University, the compiler and, to a great extent, the 

 author of Nichol's "Cyclop;edia of Physical Science," 

 and a most delightful lecturer on astronomical and 

 physical subjects. 



The tale of Lord Kelvin's achievements at Cambridge 

 has been often told — how he won the first Smith's 

 Prize and the Colquhoun Sculls, and was known as one 

 of the most promising original mathematicians of the 

 time. He returned to the University of Glasgow as 

 Professor of Natural Philosophy in 1846, and from that 

 day to this the history of his life-work has been in no 

 small measure the history of the progress of physical 

 science. There is no department of physical science 

 which he has not enriched and extended by his dis- 

 coveries. There is hardly any theory in dynamics, heat, 



