237 'Electrortietera. 



thirteen feet and depth five feet. With two hundred pas - 

 sengei's it draws forty eight inches of water. The weight 

 of iron is twelve and a half tons, rather less than that of a 

 wooden vessel of less internal dimensions. It is found to 

 be more easily tacked than a wooden boat. — Idem. 



10. Supply of Water to Glasgow. 



The city of Glasgow is supplied with water from the 

 Clyde. This stream is commonly very turbid, but the wa- 

 ter filters through a body of sand into a well on the left 

 bank of the river. Into this well dips a flexible iron tube 

 which passes across the river, lying on its bottom. Three 

 engines are employed on the other side to raise the water, 

 two of thirty-six inch cylinders and seven feet stroke, and 

 one of fifty-four inch cylinder and eight feet stroke. The 

 flexible tube is the invention of the late celebrated J. WatL 

 He derived his first idea of it from observing a lobsters tail. 



Idem. 



11. Air and Water support V^egetation. 



A fig tree, seven and a half feet high, with a stem five 

 and a half inches in circumference, is growing luxuriantly 

 in the hot house of the botanic garden of Edinburg-, com- 

 pletely suspended from the ground, and without a particle 

 of earth to nourish it. Water is thrown over it every day. 



Idem. 



12. Electrometers. 



The Abbe Haiiy has contrived two very delicate and 

 useful electrometers. 1st. A fine crystal of Iceland spar 

 attached to the end of a lever, and suspended by a silken 

 string, is electrified vitreously by simply pressing it between 

 two fingers. It retains its excitement two hours; and is not 

 much altered by dipping in water. 



2d. A support is made of sealing wax in which is stuck 

 a needle that serves as a support and centre of vibration of a 

 small bar of silver or copper terminating in balls. 



This retains its excitement much longer that when sus- 

 pended by silk. — French Journal, 



