620 



SCIENGE. 



[N. S. Vol. V. No. 120. 



patronage of Edinburgh Royal Botanical Gar- 

 dens to the Crown, and to unite the Regius 

 professorship and the University professorship 

 of botany. 



DISCUSSION AND CORRESPONDENCE. 



THE BRUCE ASTEONOMICAL MEDAL. 



To THE Editor of Science : Miss Catherine 

 Wolfe Bruce, of New York city, to whom as- 

 tronomy all over the world is indebted for 

 liberal and intelligent benefactions, proposes to 

 found a gold medal to be awarded not oftener 

 than annually by the Astronomical Society of 

 the Pacific for distinguished services to astron- 

 omy. The medal is to be international in char- 

 acter and may be given to citizens of any 

 country and to persons of either sex. The de- 

 sign for the obverse of the medal is the seal of 

 the Astronomical Society of the Pacific. The 

 medal is to be 60 mm. in diameter. The re- 

 verse is to bear this inscription : "This medal 

 founded A. D. MDCCCXCVII. by Catherine 

 "Wolfe Bruce is presented to — (name) — for dis- 

 tinguished services to Astronomy (date). ' ' 



The Astronomical Society regularly awards 

 also a bronze medal founded in 1890, by the 

 late Joseph A. Donohoe, for the discovery of 

 each unexpected comet. 



Edward S. Holden. 



Lick Observatory. 



professor scott's bird pictures. 

 In Scribner's, for April, Professor W. E. D. 

 Scott ' scores the conventional method of bird- 

 stuffing, and furnishes eight pictures of birds 

 which are stuffed according to his own ideas.' 

 Now, Professor Scott speaks from long experi- 

 ence, and what he says is largely, but by no 

 means wholly, to the point, for much of our 

 museum work is undoubtedly bad. Whether 

 or not the pictures which illustrate the article 

 and are held up as examples for us to follow 

 are any great improvement over our more recent 

 bird work is very questionable. It might seem 

 ungracious to criticise these pictures of stuffed 

 birds, but when our attention is called to them 

 by aggressive italics and special postal cards 

 criticism would seem to be invited. It therefore 

 becomes a painful duty to say that the Clapper 

 Rail and Robin are certainly not in conven- 



tional attitudes and that aside from these at 

 least three of the birds are decidedly faulty, 

 these, moreover, being birds with which Profes- 

 sor Scott should be most familiar. The Bittern, 

 p. 503, is so poised that he seems about to topple 

 over backward, while his neck and free foot are 

 both wrong. Ward's Heron, p. 501, and the 

 Little Blue Heron, p. 502, both have curves in 

 their necks which, from the structure of their 

 backbones are physically impossible. The shape 

 and articulation of the neck vertebrae of herons 

 is such that they always have more or less of an 

 angular bend in their necks, whether these be 

 extended vertically or doubled upon themselves, 

 and failure to reproduce this very characteris- 

 tic feature means failure to convey a correct 

 idea of a heron. We may accept Professor 

 Scott's strictures, but we decline to follow his 

 models. 



F. A. Lucas. 



note on a simple method foe Newton's 

 total reflection experiment. 



Demonstrators who have written for their 

 fellows seem to have overlooked the fact that 

 Newton's beautiful experiment, showing that 

 for any pair of media each color having its own 

 index of refraction has, therefore, its own criti- 

 cal angle, may be exhibited by much more sim- 

 ple and inexpensive means than the four prisms 

 usually required for that purpose. 



All that is really necessary beside the lantern 

 or other means for getting a strong sharp paral- 

 lel beam is a refraction tank, such as Wright's, 

 having glass ends. If this tank is set up in the 

 path of the beam in such a manner that the 

 light may be made to pass obliquely upward 

 into the water as for total reflection it will be 

 found that, by adjusting the depth of the water 

 in the tank and the angle of incidence of the 

 beam, the apparatus can be so arranged that 

 only red rays will emerge, all others being 

 totally reflected. Now, by diminishing the 

 angle of incidence of the pencil on the air sur- 

 face, tilting the mirror if one is used, the re- 

 mainder of the spectrum may be brought in 

 order out of the water, and, by reversing the 

 operation, sent back again totally reflected. 

 Just as in the demonstration in which the right- 

 angled prisms are employed, the image of the 



