AMERICAN INSTITUTE. 395 



dry it ; heat it in an earthen vessel up to 450° or 500^^ centigrade ; after 

 which mix it with 200 grammes of yellow prussiate of potash, quite dry 

 and pulverized. The quantity of this to be added depends, in some mea- 

 sure, on the quantity of siliceous matter contained in the clay. To this 

 mixture add 150 grammes of common salt, put all in the crucible, heat to 

 white heat. When it cools, the aluminium will be found at the bottom. 

 I claim, particularly, the application of prussiate of potash. 



SEA CABLES. 

 Sievier, of Middlesex. Patent. Coat copper conductors with bismuth 

 or tin, iron, lead, brass, antimony, zinc, nickel, or any alloy of any two or 

 more of them, previous to insulating coat. The copper conductor then is 

 more easily insulated. Electrotype the conductors. 



Mr. Seeley remarked that the rings formed of the smoke on discharges 

 of cannon are readily produced by means of a sprinkle of hydrochloric acid 

 over the bottom of an earthen or glass jar, and a phial of ammonia, open, 

 placed on the bottom ; a covering of paper over the mouth of the jar, with 

 a circular hole in the middle of it as large as a cent piece. Smoke remains 

 in the jar, if undisturbed, but on gently tapping on the paper cover, rings 

 are ejected at every tap. 



Chairman. — The regular subject is now in order — " Canal Steam or Ca- 

 loric Navigation." 



Mr. Seeley. — Steam was tried on a canal boat at Rochester, on the Erie 

 canal, some fifteen years ago. The boat and machinery were brought from 

 Europe. It was abandoned. I have thought much on this question, and 

 believe that steam will be found best. 



Chairman. — Members will recollect that steam was tried on the Dela- 

 ware canal and discontinued. 



Mr. Seeley. — The well known difficulty of damage to canals by much 

 agitation of the water, is to be always carefully provided for, let the move- 

 ment of the boat be from any motor whatever. 



Mr. C. W. Sykes has entertained the theory of propulsion on canals by 

 forced jets, or sheets of air in the water, beneath the surface. 



Mr. William B. Leonard. — The policy of this State, in deepening the 

 canals, has rendered them capable of the reception of motors, other than 

 the tedious, slow tug of hoi'ses, and therefore greatly enhanced their value, 

 as they may now perform the work of two years in one. Mr. Paine, of 

 Worcester, is now engaged in the construction of an engine, which, perhaps, 

 may turn out to be very well adapted to canal navigation. Water is im- 

 bibed by loosely twisted cords of cotton, from whose capillary moisture the 

 engine receives sufficient vapor to produce power. The contrivance is not 

 yet finished, but seems, so far, to promise a cheap, safe and adequate power 

 for engines for canal boats, if not for greater vessels and machinery. Some 

 who know more about it than I do, think it will work well. 



Mr. Finell had long pondered this question, and had formed a plan, the 

 principle of which he explained and illustrated upon the blackboard. It 



