482 ANNUAL RECORD OF SCIENCE AND INDUSTRY. 



tice of his profession ; and his attention was especially called, 

 during the siege of Paris, to the importance of having a bal- 

 loon which possessed some power of steerage. 



He has completed the first construction according to his 

 new plan, and made, as he claims, entirely successful experi- 

 ments with it. The balloon is in the shape of an enormous 

 egg, the longer axis horizontal, with an oblong car suspend- 

 ed from it. The total length is 118 feet, and its diameter at 

 the point of greatest circumference 49 feet. The rudder by 

 which the balloon is steered is a plain triangular surface, made 

 of unvarnished calico, and constructed so as to turn easily on 

 its forward extremity. The car is of wicker-work, containing 

 a windlass for the screw, eight men to manage it, and is capa- 

 ble of carrying fourteen persons. 



The rudder is fixed to the balloon itself, and the screw is 

 below it and immediately attached to the car, and having 

 only two blades, so that when the ground is touched they can 

 be placed horizontally to escape injury. The windlass which 

 turns the screw is worked by four to eight men. The enve- 

 lope of the balloon is composed of white silk. 



The constructor does not pretend to be able to make a di- 

 rect movement against the wind, but only to deviate from its 

 direct set when running before it. He expects to be able to 

 tack to the right or left, but does not hope to be able to beat 

 to the windward. There is a second balloon attachment to 

 the bottom of the main balloon, forming a kind of compart- 

 ment, occupying about one tenth of the cubic space of the 

 balloon, and serving to keep it stiff and of the required shape. 



In the experimental trip of M. De Lome a half gale was 

 blowing, and the result answered entirely to his expectations. 

 The screw drove the balloon about five miles an hour quick- 

 er than the wind was blowing, and by the use of the rudder 

 the course of the balloon could be altered eleven degrees, ei- 

 ther way, from the set of the wind. 12 A, Feb. 22, 1872, 334. 



NEW DETONATING MIXTUKE. 



A new detonating mixture is made by bringing together 

 equal parts of nitrate of potash and of acetate of soda; these 

 substances, when exposed to heat, enter into new combina- 

 tions, in which the salts are converted into gases, with a vio- 

 lent explosion. 19 (7, February 24,1872,64. 



