528 TRANSACTIONS OF THE AMERICAN INSTITUTE. 



The chairman exhibited specimens of peat taken from the ground 

 in Prospect Park, Brooklyn. It covers an extent of about 500 

 acres, and is about 15 feet in depth. It did not, however, appear 

 to be a good quality of peat for burning, on account of the earthy 

 matter mingled with it. 



Mr. L. B. Page presented a vial of crude petroleum as black as 

 coal. A portion of the same lot of oil he had simply passed 

 through boneblack, which made it almost as clear as water ; but 

 in passing the oil through boneblack there is a loss of about 20 

 per cent. This oil is an excellent lubricator; it does not become 

 gummy. iSome persons who use it perfer it to sperm. 



The chairman presented the following paper: 



Eeseaeches in Magnetism and Electhicity. 



H. Wilder, Esq., England, has made a series of interesting 

 experiments in electricity, and claims to have discovered a means 

 of producing dynamic electricity in quantities unattainable by any 

 apparatus hitherto constructed. He has found that an indefinitely 

 small amount of magnetism, or of dynamic electricity, is capal)le 

 of inducing an indefinitely large amount either of magnetism or 

 of dynamic electricity. His apparatus consists of a hollow com- 

 pound cylinder of brass and iron, called by him a magnet cylin- 

 der, having an internal diameter of one and live-eighths of an inch. 

 On this cylinder could be placed, at pleasure, one or more perma- 

 nent horse shoe magnets; each of which weighs about one pound, 

 and sustains a weight of about ten pounds. An armature is made 

 to revolve rapidly in the interior of the cylinder, in close prox- 

 imity to its sides, but without touching. Around this armature 

 163 feet of insulated copper wire, 0.03 inch in diameter, is coiled, 

 and the free ends of the wire are connected with a commutator, 

 fixed upon the armature axis, for the purpose of taking the alter- 

 nating pulsations of electricity from the machine in one direction 

 only. The direct current of electricity is transmitted through 

 the coils of a tangent galvanometer, and as each additional mag- 

 net is placed upon the magnet-cylinder, it is found that the 

 quantity of electricity generated in the coils of the armature is 

 very nearly in direct proportion to the number of magnets thus 

 applied. 



Experiments were also made to find out what relation existed 

 between the sustaining power of the permanent magnets on the 

 magnet-cylinder and that of an electro-magnet excited by the 



