548 Chronicles of Science. [Oct., 



has compiled from various disconnected registers of local observa- 

 tions for short periods lying at the observatory of St. Petersburgh. 

 The stations are very widely distributed over Europe and Asia. 



The Eeport of the Central Physical Observatory, by Prof. H. 

 Wild, the Director, consists mainly of an account of the condition of 

 the observatory, and a catalogue and description of instruments. As 

 no report had been published since 1864 it was necessary to take 

 stock, and to publish the account for the information of the Kussian 

 public. The only matter of general interest is that Prof. Wild 

 appears to have finally decided not to employ photographic self- 

 recording instruments at the normal stations, owing to their serious 

 initial cost and the expense and trouble of working them. 



Dr. Prestel, of Emden, has published a pamphlet entitled ' Der 

 Sturmwarner,' in which he commences by discussing the facts of 

 storms, and the possibility of giving telegraphic intelligence of their 

 approach. On reading this part of the paper we are disappointed 

 to find that Dr. Prestel has not made himself acquainted with the 

 latest facts of the subject. The principle of his storm-warner is 

 similar to that of Piddington's horn circles. 



He makes four assumptions. 



I. That the barometrical reading at the centre of the storm is 

 28 * 78 ins. on the mean. 



II. That the wind blows in circles round it. 



III. That the diameter of the storm is nearly constant. 



IV. That the difference between barometrical readings for a given 

 distance in all parts of the storm, or the " gradient," is constant. 



If these four postulates be granted, the use of the transparent 

 diagram is perfectly simple and intelligible, but as there is no foun- 

 dation for any one of them, the whole reasoning falls to the ground. 



Another book the utility of which we fail to discover, although 

 it has been favourably noticed in some newspapers, is ' The Wind in 

 his Circuits,' by Lieut. E. H. Armit, K.N. 



The author proposes to subvert Maury's theory of the wind by 

 facts drawn from his own experience. A few examples will suffice 

 to show the character of his arguments. The italics are his : — 



" The trade winds are very damp moist winds, heavily charged 

 with vapour : every cubic inch of them containing millions upon 

 millions of minute globules of water. On entering the equatorial 

 calm belt, the process these globules undergo is simply that of being 

 turned into steam.'"* 



" The easterly wind is formed of compressed vapour or steam."^ 



" Lightning and thunder are caused by the ' Arctic current ' 

 descending to fill any vacuum that may suddenly be formed in the 



warm currents below it The ' Arctic current ' in rushing 



down would grate against the sides of the warm air of the under 

 * P. 24. f P. 57. 



