452 



SCIENCE. 



[N. S. Vol. IV. No. 91. 



The 'Brooklyn' is 400 feet long, 64| feet beam, 

 with a load draught of 24 feet. Her load dis- 

 placement is computed at 9,153 tons and her 

 engines are rated at 16,000 I. H. P. The con- 

 tract speed was 20 knots at a displacement of 

 8,250 tons ; but, as in the majority of later con- 

 structions, especially by the Cramps, the build- 

 ers of the ' Brooklyn,' this speed is greatly ex- 

 ceeded on trial, and will undoubtedly even be 

 somewhat exceeded when in sea-going trim. 

 The contractors will make a bonus of $350,000 

 to $400,000 on the excess of trial speed over 

 the minimum of the contract. This ship is 

 considered unrivalled in conjoined power and 

 speed. 



The proposed armament consists in its princi- 

 pal battery, of eight 8-inch B. L. rifles with 

 twelve 5-inch and some smaller ordnance. 

 The armor is light — 8-inch. This ship is a 

 thousand tons heavier than the ' New York ' 

 and designed for one knot less speed ; but she 

 will probably fully equal that ship in this re- 

 spect. The battery of the 'Brooklyn' is 

 heavier, by two 8-inch and also by carrying 

 5-inch guns in place of 4-inch. 



This is one of the most marvellous of all the 

 examples of modern naval construction yet 

 produced, all things considered, and its concen- 

 tration of speed with offensive and defensive 

 power is probably without equal. Perhaps we 

 may also conclude that the performance of the 

 ' Brooklyn ' affords the best possible evidence 

 of the wisdom of the policy of the creators of 

 modern navies, and particularly of that of the 

 United States, in securing that union of mathe- 

 matical and scientific professional training with 

 practical experience in the management of 

 these intricate machines at sea which has placed 

 our own engineer and construction corps on so 

 high a plane and has given them the needed 

 theoretical and practical ability to design such 

 marvels of naval architecture as are the float- 

 ing machines of which we now see our navy 

 composed. R. H. Thurston, 



CHEMISTRY. 



It is well known that all atomic weight de- 

 terminations of tellurium have given results 

 higher than would justify the place it holds in 

 the periodic system, and have led to the suppo- 



sition that some impurity of higher atomic 

 weight may be present. Brauner's determina- 

 tions give the figures 127.64; Staudenmaier 

 using different methods has recently confirmed 

 this, his number being 127.6. Acting upon the 

 idea that both of these results were obtained 

 on tellurium from the same or similar sources, 

 Chikashige has made determinations of a Ja- 

 panese tellurium which occurs in a massive 

 sulfur, uncontaminated with any of the heavy 

 metals. The method he used is the same as 

 that used by Brauner. The atomic weight 

 found is 127.61 as a mean of three closely con- 

 cordant experiments, and confirms the previous 

 results. The anomaly of tellurium, as well as 

 that of cobalt in the periodic system, thus re- 

 mains as unexplained as before. 



In a recent Journal of the Chemical Society 

 Herbert McLeod published further investiga- 

 tions on the liberation of chlorin in the making 

 of oxygen from potassium chlorate and manga- 

 nese dioxid. In opposition to the work of Dr. 

 Brunck, he shows clearly that the active gas 

 liberated is chlorin and that no ozone is evolved. 

 The reaction taking place is probably 



2Mn02+2KC103 = 2KMnOi+Cl2+0 



2KMnO^ = KjMnOi+MnOa+Oa 

 KaMnO.-f CI2 == 2KCl+Mn02+02 

 The manganese dioxid is continuously repro- 

 duced, and only a very small quantity of chlorin 

 ultimately escapes absorption by the manganate. 



J. L. H. 



GENERAL. 



Among the public lectures to be given in con- 

 nection with the sesquicentennial celebration of 

 the founding of the College of New Jersey and 

 the ceremonies inaugurating Princeton Univer- 

 sity will be four lectures by Prof. J. J. Thom- 

 son on 'The Discharge of Electricity in Gases,' on 

 October 13th, 14th, 15th and 16th ; four lectures 

 by Prof. Felix Klein on 'The Mathematical 

 Theory of the Top,' October 12th, 13th and 15th, 

 and one lecture by Prof. A. A. W. Hubrecht on 

 ' The Descent of the Primates, ' on October 19th. 

 Men of science in departments of study repre- 

 sented by the lectures are invited to attend, but 

 should make application for tickets before 

 October 5th to Prof. William Libbey. 



Nature states that Dr. W. R, Gowers will de- 



