.8 



NA TURE 



\_Aitgnst 5, i8So 



Expansion of Glass by Heat 



The reproduction in your " Pliysical Notes" (Nature, vol. 

 xxii. p. 157) of Mr. K. H. Ridout's neat experiment for illiis- 

 tratint' the " Expansion of Glass by Heat " {Phil. Mag. for 

 June, iSSo), recalls to mind an equally striking method of ex- 

 hibiting this property of glass to a cla^s of students in physics. 

 Select a straight glass tube 50 or 60 centimetres in length and 

 I or 2 centimetres in diameter. Place it transversely in front of 

 a fire, in a horizontal position, properly supported near its two 

 eiiJs on two horizontally-adjusted rods of hard smooth wood of 

 about the same diameter as the tube ; the glass tube will gradu- 

 ally roll tmairds tliefire. Now let the supporting rods be trans- 

 ferred to either side of the centre of the tube, so as to support it 

 near its middle ; the tube will now gradually 7-cll from the fire. 



It is scarcely necessary to remind the reader that the greater 

 dilatation of the glass on the side of the tube which is nearer 

 the fire renders it curved, with the convexity next to the source 

 of heat, so that, when supported near the ends, \\\e falling of 

 the central farts of the curved tube rolls it towards the fire ; 

 but when supported near the middle the falling of the ends of 

 the similarly curved tube rolls it front the fire. These experi- 

 ments, it is evident, succeed better when the cold tube is first 

 adjusted near the fire than when it has been so long exposed to 

 the action of the heat as to have become heated throughout its 

 mass. 



It seems that about the year 1740 this behaviour of glass tubes 

 under similar conditions was noticed by Mr. C. Orme, of Ashby 

 de la Zouch, while heating some barometer tubes. The Rev. 

 Granville Wheler, who carefully verified the experiments of Mr. 

 Orme, very correctly ascribes the phenomena to the distortion of 

 the tube due to the action of heat (vide Phil. Trans., No. 476 ; 

 also Edinburgh Encyclop,edia, 1st Am. ed., 1S32, vol. ix., 

 article "Glass," p. 773). Nevertheless in the United States 

 this behaviour of glass tubes, when placed before a fire, has been 

 frequently classed among the unexplained mysteries of glass I As 

 recently as 1S65 INIr. Deming Jarves, of Boston, in his little 

 volume entitled " Reminiscences of Glass-Making," p. 10 (2nd 

 ed., N.Y,, 1S65), refers to the phenomena, but with not one 

 word of explanation. In fact not long ago some of our semi- 

 scientific journals characterised these phenomena as mysterious 

 and inexplicable. Hence I have for the last twenty or thirty 

 years employed such experiments, not only as exhibiting visible 

 manifestations of the expansion of glass, but also as affording an 

 instructive and significant illustration of how completely the most 

 obvious mechanical residts may be overlooked or ohsciired under 

 the inspi7-atio7i of the propetisity to seek for the mai'vellous in 

 nature t ' John" LeConte 



Berkeley, California, July S 



Fascination in Man 



Having frequently seen it stated in popular works on natural 

 history as well as in some books of travels (chiefly Australian) 

 ihat certain snakes possessed the power of so fascinating, with 

 their gaze, birds and other creatures as to be able to seize upon 

 and devour them without any difficulty, I am induced to inquire 

 .f such a power is peculiar to the serpent tribe or not, and inci- 

 lentally to ask if any instances of its influence or extension can 

 be traced, up the scale of creation, to man himself. Being of 

 opinion that such is the case, while it has occurred to me that 

 many of the fatal accidents that occur in the streets of large 

 cities, such a-. London, &c., might be ascribed to some such 

 agency or sensation, I am induced to call attention to the cir- 

 cumstance in these pages, and to submit the following as my 

 own personal contributions tow ards the inquiry : — 



Describing certain incidents of the siege of Gibraltar, Drink- 

 water says, "History," p. 75, that "on the 9th Lieut. Lowe 

 . . . lost his leg by a shot on the slope of the hill under the 

 ';astle," and the italics are mine throughout. " He saw the shot 

 before the fatal effect, but -aas fascinated to the spot. This 

 sudden arrest of the faculties was not uncommon. Several 

 instances occurred to my own observation when men totally free 

 ■'lave had their senses so engaged by a shell in its descent that, 

 ■'hough sensible of their danger, even so far as to cry for assistance, 

 ! hey have been immediately fixed to the place. But what is more 

 remarkable, these men have so instantaneously recovered them- 

 elves on its fall to the ground as to remove to a place of safety 

 before the shell burst." 



Alluding to the first casualty that occurred at Cawnpore during 

 lie siege of the entrenchment there in 1857, Mowbray Thom- i 



son says ("The Story of Cawnpore," p. 66) that "several of u; 

 saw the ball bounding towards us, and he (McGuire) evidently 

 saw it, but, like many others whom I saw fall at different times, 

 he seemed fascinated to the spot " ; and an old and now deceased 

 departmental friend, who went through the whole Crimean 

 campaign, assured me that he was once transfixed (fascinated, lie 

 called it) after this fashion in presence of a shell that he saw 

 issuing from Sebastopol, and whose every gj-ration in the air lie 

 could count. Other militai-y friends have' discussed the point 

 with me in this same wise, and I think there is some allusion t^ 

 it in one or other of the works of Larry, Guthrie, Ballingall, or 

 others of that ilk. W. CURRAN 



Warrinc;ton 



Monkeys in the West Indies 



I.N consequence of my removal from the West Indies to the 

 West Coast of Africa, and of illness since my an-ival here, I 

 have not until now had time to read in the back numbers ot 

 Nature the controversy on the subject of " Monkeys in the 

 West Indies," which, it may be said, I created by my com- 

 munication in Nature, vol xxi. p. 131. I trust, therefore, I 

 now may be permitted to reappear on the scene and to sum up 

 my case. 



In my communication I quoted, from Prof. Mivart's lecture 

 on " Tails," an extract which appeared in your columns 

 (Natiirf, vol. XX. p. 510), viz. : " Monkeys are scattered over 

 almost all the warmest parts ol the earth save the West Indies, 

 Madagascar, New Guinea, and Australia," and I added, with 

 the utmost respect for Prof. Mivart, that the above statement 

 was not " quite correct," adducing as proof the fact that they 

 were found in St. Kitts, Nevis, and Trinidad. Mr. Sclater, 

 F.R.S., the distinguished zoologist, answered my letter (Nature, 

 vol. xxi. p. 153), explaining that Prof. Mivart was correct in his 

 statement; that the monkeys of St. Kitts were not "indi- 

 genous" to that island, and that Trinidad origin.ally was part of 

 the mainland of South America. Mr. Sclater said nothing 

 about the Nevis monkey. Dr. Imray of Dominica followed 

 with a quotation from Pere Labat (Nature, vol. xxi. p. 371), 

 and as regards St. Kitts and Trinidad, the monkey question was 

 closed. 



But it subsequently came to my knowledge, through hearsay 

 evidence, that monkeys existed in large numbers in Grenada, 

 one of the Windward group of islands, although travellers and 

 historians from the time of Pere du Tertre to that' of Bryan 

 Edwards seemed to be ignorant of the fact. As I had left the 

 West Indies when I obtained this information, I at once called 

 Dr. Imray's attention to it, begging him to ascertain its accu- 

 racy and then to communicate with N.\tupe. Dr. Imray has 

 done so (Nature, vol. xxii. p. 77), and, by a curious coincid- 

 ence, his letter appears in the same number in which a Grenada 

 correspondent, signing himself D. G. G., charges me with being 

 " quite as much in error as Prof. Mivart," and makes me .say 

 that "the only islands in' the {West Indies -.ohere monkeys are 

 to be found are St. Christopher {i.e., St. Kitts] and Nevis." The 

 italics are my own, but I think D. G. G. should at least be 

 careful to quote accurately. 



I have no wish to trespass further on your valuable space. 

 Whit I desired to show and what I have shown is that monkeys 

 do exist in many of the West India Islands, and that, although 

 nearly four hundred years have passed away since the discovery 

 of the islands, their natural history is still very imperfectly 

 known. And yet these islands are within easy steaming distance 

 from England ; they are inhabited by people -whose kindness 

 and hospitality to visitors are proverbial. Their mountains afford 

 all the varieties of healthy climate, and for the botanist, the 

 geologist, the entomologist, and the man of science generally, 

 there are few, if any, richer fields of instraction and enjoyment. 



Government House, Cape Coast Castle, Edmund Watt 

 Gold Coast, July 3 



Can any of the readers of Nature inform me^ whether the 

 sharp clicking noises produced on removing Utriculari.t from 

 the water (particularly for the first time) have been noticed or 

 described ? I have not succeeded in determining the species, as 

 the plants are not yet in flower. J. W. CLARli 



R.I.E. College, Cooper's Plill, July 30 



