July 26, 1900J 



NATURE 



29: 



Bullock Clark, on the establishment and organisation of 

 the Maryland Weather Service ; a description of the 

 physiography of Maryland, by Dr. Cleveland Abbe, jun. ; 

 a report on the meteorology of Maryland, by Dr. Abbe, 

 Mr. F. J. Walz and Dr. O. L. Fassig ; and a contribu- 

 tion on the aims and methods of meteorology, by Prof. 

 Cleveland Abbe, already noticed in these columns (vol. 

 l.xi. p. 448). The illustrations are numerous, instructive, 

 and of a very high class, most of them being full-page 

 collotype plates or lithographs. No State or country 

 has given to the scientific world a volume in which the 

 operations of the "Weather Service" are interpreted 

 more liberally, or the work presented in a more elaborate 

 format. 



Volta e la Pila. By Prof. Augusto Righi. Pp. 40. 

 (Milan : Tip. Bernardoni di C. Rebeschini, 1900.) 



This is an inaugural discourse delivered by Prof. Righi 

 on September 18, 1899, at the National Electrical Con- 

 gress at Como. It deals with (i) the science of electricity 

 prior to Volta ; (2) the scientific work of Volta considered 

 apart from his discovery of the pile ; (3) Galvani's dis- 

 covery of electricity of contact ; (4) the pile ; (5) the 

 theory of the pile ; and (6) conclusions. In an appendix, 

 Prof. Righi gives a note on the theories of the pile, in 

 which he expresses favourable opinions on the " osmotic " 

 Ktheory. 



LETTERS TO THE EDITOR. 

 \The Editor does not hold himself responsible for opinions ex- 

 pressed by his correspondents. Neither can he undertake 

 to return, or to correspond with the writers of, rejected 

 manuscripts intended for this or any other fart of Nature. 

 No notice is taken of anonyniotts cofiimunications.] 



An Optical Phenomenon. 



In connection with Prof. Simon Newcomb's letter on " Terres- 

 trial Gegenschein" (Nature, October 5, 1899) and the sub- 

 juent letters of Mr. Mallock (Nature, October 12 and 



^November 9, 1899), I desire to call attention to an analogous 

 id very beautiful phenomenon of perspective which I should 

 ive mentioned at the time but that the winter season of the 

 year is not favourable to its observation in this country. 



•' When the sun is high and shining brightly in a clear sky, let 

 an observer stand so that the shadow of his head falls on the 

 surface of water that is deep, clear, but not quite clear, and 

 slightly agitated by the wind. He will observe that from the 

 place where the shadow of his head falls shafts of light seem 

 to radiate in all directions. When once well observed, the 

 phenomenon is very striking, but it has surprised me to find 

 how few persons have noticed it. I first observed it many 

 years ago, when I used daily, about mid-day in summer, to 

 cross the bridge over the channel leading to the boat store in 

 the Portsmouth Dockyard, near the main entrance. But it was 

 not till a year later, on Ulleswater, that I found the explana- 

 tion. The lake was there turbid in parts from the washings 

 of mines, but quite clear in others. Standing up in a boat, one 

 could see the phenomenon very clearly where there was very 

 slight turbidity, but not if the water was quite clear, nor if there 

 was much turbidity, and never in a dead calm. This gave the 

 explanation. The convexities of the surface, when there is a 

 slight agitation, acting as lenses, split up the otherwise uniform 

 illumination into separate, parallel shafts of light, each consist- 

 ing of slightly convergent rays, which, traversing the liquid, are 

 rendered visible by the suspended particles that they illuminate. 

 These shafts seen in perspective have their point of apparent 

 convergence exactly opposite to the sun, i.e. in the shadow of 

 his head. If the water is smooth, there are no particles to 

 illuminate and reveal the shafts ; if too turbid (or too shallow), 

 the light does not penetrate far enough. If the sun be too low 

 in the sky, too little light enters the water ; if it shines through 

 clouds, so that the source is diffuse, a uniform illumination 

 results. Hence the rays are not easily noticed in winter. 



After the phenomenon has once been well seen under such 

 circumstances as I have described, one can hardly enter a boat 



NO. 1604. VOL. 62] 



on a bright day without being haunted by it, and realising that, 

 although the shadow of one's head may not actually fall on the 

 water, yet every streak of light in the water radiates from it. 

 A. M. Worthington. 

 R.N Engineering College, Devonport, July 22. 



Temperatures of Recently Killed Chamois. 



Mr. E. N. Buxton, in his fascinating "Short Stalks" 

 remarks (p. 38, footnote) : " A friend of mine once took the 

 temperature of a freshly killed chamois, and it stood at 130° F." 

 There is no doubt that many professional chamois hunters believe 

 that the temperature of the animal is considerably higher than 

 that of domestic animals. 



During the last three years I have determined the rectal tem- 

 perature of twenty-nine recently killed chamois. 



These may be divided into three ciasSes. 



A. — Those successfully stalked and dropped dead by the first 

 shot. ( 1 2 observations. ) 



With two exceptions, the temperatures, taken in every case 

 within five minutes of death, lie t)etween loi°'l and I0l'''9, the 

 average being about ioi°'5 F., or 38° 6 C. 



The two exceptions were (i. ) a kid four or five months old, 

 the temperature of which was I03°'2 F., or 39°'6 C, and (ii. ) a 

 doe which had received a severe flesh-wound in the back eight 

 days previously, the temperature of which was 102° '4 F. , or 

 39^-1 C. 



B. — Those shot au galop. (7 observations.) These animals 

 all dropped dead in their tracks, or died almost immediately. 



The temperatures on the whole were found to be distinctly 

 higher than in class A, being ioi°'5, I02°"3, I02°'4, I02°'9, 

 102° '9, I03°*5 and 104° '5 respectively. 



The first four of these had run from 40 to 50 yards, the fifth 

 about 200 yards, and the last two about 100 yards. The last 

 two were young bucks, which, to judge from the appearance of 

 their incisor teeth, were four and three years old respectively. 



C. — Those wounded at the first shot, but only brought to 

 bag after some interval. (10 observations.) 



Here the temperatures are, on the whole, still higher. 



The lowest (I0I°7) was that of an animal which ran 50 yards 

 after the first shot, and was then dropped dead by a second. 



The next (102° -4) ran about 300 yards. The third (i02'''9) 

 was wounded in the stomach, then walked about 250 )ards 

 towards me, and was dropped by a second shot at about 30 

 yards. 



The fourth (103° "i) ran about 200 yards. The fifth and sixth 

 (i03°'3 and 103° '5) were shot through the kidneys, but were not 

 killed outright by the shot. 



The remaining four showed temperatures of 104" '9, 105° 6, 

 1 06° '2 and 1 06° 7. 



Of these the first had its fore-leg broken, and was recovered 

 twelve hours later. 



The second and fourth were recovered about half an hour after 

 being wounded. 



The third was an animal whose hind-leg was broken. It then 

 escaped into another valley, and hid itself in a cave on a rock- 

 wall, where it was spied about four hours later. A second shot 

 failed to hit it, but drove it out of tlie cave. It then tried to 

 climb the steep rocks above it, and after twice failing to over- 

 come a fnauvais pas, slipped and fell about 100 feet, and was 

 killed by the fall. 



Results similar to these were obtained in 1898 by a Swiss 

 friend of mine. Some of the animals were driven by dogs, and 

 these always showed a higher temperature than those stalked 

 and killed by the first shot, the temperatures of the driven 

 animals varying from 103° '6 to io5°*8. 



The highest temperature obtained by him was 107° '6 (42° C). 

 This was an animal which was severely wounded in the back, 

 then lost till twenty-four hours later, when it was found and 

 killed by a dog. 



How far the average temperature given under A represents 

 the normal temperature of the living chamois, I am unable to 

 say, because I do not know to what extent sudden death by a 

 bullet would be likely to affect the reading of the thermometer. 

 Perhaps seme physiologist would kindly throw some light upon 

 this point. 



To save the trouble of calculation to any foreign reader who 

 may see this letter, I may add that 38° C. = 100° -4 F., 39° C. = 

 i02''-2 F., 40° C. - 104° F., 41° C. = lOS'-S F., 42° C. = 

 io7''-6 F. G. Stallard. 



Rugby, July 12. 



