392 Progress of Invention. 



and a solution of resin in turpentine. The printing is effected with 

 rollers, and the colours are vitrified by heat, no distortion taking 

 place. 



A New Anemometer. — This self-registering instrument, the in- 

 vention of M. Radan, consists of a pencil moving uniformly down a 

 vertical cylinder, or from the centre to the circumference of a disc, 

 on each of which paper has been placed. If the cylinder, or disc, 

 is stationary, the line drawn on the paper placed on the cylinder 

 will be perpendicular to the circumference of its base ; and that on 

 the paper placed on the disc will correspond with one of the radii 

 of the disc. The pencil is connected with a Robinson anemometer 

 in such a way that, when the cups have made a certain number of 

 revolutions, it is lifted from the paper, an interruption being thus 

 produced in the line drawn upon it. And the cylinder, or disc is 

 made moveable on an axis, at the upper end of which is fixed an 

 ordinary weathercock. The paper on the cylinder, or disc, is 

 divided by lines into spaces which correspond with equal portions 

 of time. The interruption, therefore, in the line made by the 

 pencil, corresponding to a given time, will show the velocity of the 

 wind during that time. And the deviations of the pencil-line from 

 a round line will show its direction daring any given time. 



A New Cannon. — It is a matter of great importance that the 

 force produced by the explosion shall be gradually communicated 

 to the projectile. The inertia of the latter renders this necessary ; 

 since, though motion may be communicated very rapidly, it still re- 

 quires a certain time for transmission. A powder may explode with 

 such velocity, as that instead of the projectile being driven forward, 

 the gun shall be burst ; such would be the case were any fulminating 

 compound substituted for gunpowder. Among the means used for 

 securing a gradual communication of the explosive force to the bail 

 is a cannon recently invented in America, and which is said to 

 afford excellent results. Instead of the powder being accumulated 

 in one chamber behind the ball, only a portion of it is placed there, 

 the remainder being introduced into lateral chambers in front of 

 the ball, and communicating by openings w T ith the interior of the 

 gun; when the powder has been placed in any one of these 

 chambers, the opening which forms the communication between it 

 and the exterior is closed by a screw. As soon as all have been 

 charged, the piece is ready to be fired ; and the instant the ball has 

 passed the opening leading to one of these chambers the intensely 

 heated gases following the ball, enter it, and exploding the powder 

 which it contains, a new impulse is given to the projectile. This 

 takes place after the latter passes each of the chambers ; the explo- 

 sive force of the powder being separated into successive portions and 

 therefore rendered more effective. The explosion being divided 

 there is less clanger of the gun bursting; but the complication, and 

 the time required for loading will be found more or less objectionable. 



A Self-Registering Mariner's Compass. — A mariner's compass 

 which is capable of registering the ship's course, and is by no means 

 complicated, has been invented by the Baron AVobel-Jarlsberg, a Nor- 

 wegian nobleman, connected with the marine. A time-piece, is placed 



