Intelligence and Miscellaneous Articles. 65 



backwards, is added in the new form of shot to the usual quantity of 

 projectile force. The experiments made with shot weighing up to 

 twenty-five pounds, were successful both as to force and direction 3 

 and the extraordinary advantage gained as to lightness in the appa- 

 ratus necessary to throw the shot, was proved by one man taking all 

 that was necessary to Primrose-hill, the place of experiment. 



Some fine fulgurites or lightning sand-tubes were placed on the 

 library tables. 



May 30. — Mr. Curtis gave a lecture on the structure and physi- 

 ology of the Ear in man and animals, illustrated by drawings and 

 anatomical preparations. 



June 6. — Mr. Burnet gave an illustrated account of the experi- 

 ments recently made by himself and Mr. Mayo, on the irritability of 

 the sensitive plant, and extended his observations to the irritability 

 and supposed nervous structure of plants in general. Their experi- 

 ments accord with those of Dutrochet, as far as the two series run 

 parallel. When a sensitive plant has been made to droop, Mr. Burnet 

 finds that if the part in which the moving power resides is blackened 

 so as to absorb the light of the sun, the restoration of the plant to its 

 natural state is very much longer before it takes place. He also 

 found that at the moment the expansion at the foot of the leaflets or 

 other parts were touched to produce the motion of the plant, it 

 changed colour. 



June 13. — A full account of the recent and present state of the 

 Thames Tunnel was given by Mr. Faraday, illustrated by Mr. 

 Brunei's drawings and models. The peculiar nature of the ground 

 in which the tunnel lies, the occurrence of springs in the soil, the 

 extraordinary manner in which they affect it during the rise and fall 

 of the tide, were stated and explained ; and then the present state 

 of the tunnel, now perfectly free from water, and the intentions of 

 the engineer with regard to its future progress, were described. 



These evening meetings then closed for the season. 



XL Intelligence and Miscellaneous Articles. 



DIRECT METHOD OF ASCERTAINING THE VELOCITY OF CAN- 

 NON-BALLS. 



L1EUT.-GEN. HELVIG, in the Prussian service, has invented a 

 direct and certain method of measuring the time which a can- 

 non ball or bullet takes to pass through a certain space. His process 

 consists in disengaging by means of the ball or bullet the detent of 

 a third's watch (une detente de montre d, tierce) at the moment when 

 the ball or bullet quits the mouth of the piece, and to stop the same 

 watch by means of the ball or bullet at the instant when it reaches 

 the mark. The numerous experiments which he has made, present 

 already the most interesting results. He has communicated this 

 notice in order to establish his right to the invention, but intends 

 shortly to publish a full detail of his experiments upon the subject. — 

 Bulletin des Sciences Militaires, p. 119. 



New Series. Vol. 4. No. 19. July 1828. K chryso- 



