October 22, 1886.] 



SCIEmjE, 



367 



from the centime of gravity to the point of attach- 

 ment of the string shall be three times the distance 

 between that point and tlie centre of pressure. 



— A recently completed iron water-tower, 250 

 feet high at Sheepshead Bay, near Coney Island, 

 Tvhile being tested a few days ago, gave way at 

 the base, and fell, shattered, to the ground when 

 the water reached a height of 227 feet. 



— The meeting of the Public health association 

 was closed at Toronto recently. Dr. George M. 

 Sternberg was elected president. Prof. Charles N. 

 Hewitt fii'st vice-president, Prof. C. A. Lindsley 

 second vice-president, and Dr. Irving A. Watson 

 secretary, for the coming year. 



— Pretty much the whole of the September 

 number of the Journal of the Society for psychical 

 research is devoted to an interesting tale of a 

 ' haunted house.' 



— Arrangements are being made at Newcastle- 

 upon-Tyne for holding there a mining, engineer- 

 ing, and industrial exhibition (international and 

 colonial) in 18s7, to mark the jubilee year of the 

 reign of the queen. 



— Dr. Schweinfurth has, says iVafitre, addressed 

 to all Europeans, especially physicians, residing in 

 Egypt, an inquiry as to whether, so far as they 

 are aware, families of northern origin settling in 

 Egypt do, or do not. die out within three genera- 

 tions, or whether the race is capable of being per- 

 petuated beyond that limit. 



— It is stated by the London Engineering that 

 a dirigible balloon of colossal dimensions has been 

 for some time in course of construction in Berlin. 

 It is 500 feet in length, 50 feet in diameter, and 

 weighs 43,000 pounds. The propelling power con- 

 sists of two steam-engines of 50 horse- power each. 



— In a recently patented soda-motor, intended 

 for use on street-railways, the process of generat- 

 ing steam is as follows : the caustic soda, which 

 is contained in a reservoir surrounding the 

 steam-boiler, is raised to a high initial temperature 

 by means of jets of burning gas or petroleum, 

 thus evaporating all moisture from the soda. The 

 heat from the soda produces steam in the boiler, 

 Tvhich is applied to an ordinary engine ; the ex- 

 haust steam from the engine is then absorbed by 

 the soda, producing heat sufficient to generate 

 steam, until the soda is supercharged with 

 moisture, when the jets of flame, which in the 

 mean time have been dispensed with, are again 

 ignited to regenerate and reheat the soda. The 

 operation may be repeated continuously. This 

 is a modification of the soda-motors which have 

 been in use several years past in this coimtry and 

 in Europe. 



LETTERS TO THE EDITOR. 



*t* Correspondents are requested to be as brief as possible. The 

 writer's name is in all cases required as proof of good faith. 



How astronomers may work. 



In your issue of Oct. 15, 1 notice the reply of Pro- 

 fessor Holden to your comment on his scheme of 

 inviting the leading astronomers of the world to visit 

 Mount Hamilton, one at a time, to use the Lick tele- 

 scope when not in use by the regular observers. I 

 think Professor Holden is unfortunate in his selection 

 of examples of good work done at high elevations. 

 Each one of his examples miu;ht be quoted as an in- 

 stance where excellent results were gained as the 

 reward of continuous work by a skilled observer, 

 using the instrument with which he was most familiar, 

 and in a field of research where his powers of obser- 

 vation were at their best. Probably we should know 

 less than we now know about radiant energy, if Mr. 

 Burnham had gone to Mount Whitney to use the 

 bolometer, in place of Professor Langley and Mr. 

 Keeler. And we may be quite certain Professor 

 Langley would not have added to his reputation, 

 had he gone to Mount Hamilton to use Mr. Burn- 

 hara's telescope, searching for double stars. Doubt- 

 less, many men will be glad to have an opportunity 

 to look through the Lick telescope, to note how 

 familiar objects appear whan seen with an instru- 

 ment of its anticipated perfection and power. But 

 it does not seem possible that any results of scientific 

 value can be obtained from such scrappy, disjointed 

 work as is proposed by Professor Holden. T. 



New York, Oct. 19. 



Larval amblystomas for laboratoty work. 



During the past summer I have sent to the Smith- 

 sonian institution several hundred living specimens 

 of larval and adult amblystomas. These were to 

 meet the demand for these important forms on the 

 part of special workers, and the biological laboratories 

 both in this country and Europe, a number of them 

 having been sent to M. Chauvin in Germany. 



Quite recently, however, I have received a num- 

 ber of other applications from colleges and other 

 points, requesting a few specimens of these animals 

 for their investigations, and for the use of biological 

 students. To meet these latter demands, I send by 

 express to-day an unusually fine lot of some two hun- 

 dred and fifty living larval amblystomas, and two 

 adults, to Professor Baird, at the Smithsonian insti- 

 tution, Washington, D.C., where^ if proper applica- 

 tion be made for them, I am assured they will be 

 sent to any point in accordance with the regulations 

 governing the distribution of such material from 

 that institution. R. W. Shufeldt. 



Fort Wingate, N. Max., Oct. 8. 



Polydactylism. 



An instructive example of this abnormity was 

 under my observation at about the time Dr. LeConte 

 published his interesting letter upon the subject 

 {Science, Aug. 20), and Mr. John B. Smith of the U.S. 

 national museum, in a subsequent number, added 

 his own observations {Science, Sept. 3) in regard to it. 



The case I refer to is that of a man (F. G.) hving 



