221 



tion for the Astronomical Determination of Minute Angular 

 Changes," was presented, and being read in part, was referred 

 to the officers and council. 



Ml'. Franklin Peale submitted to the examination of the 

 members of the Society, some specimens of the manufacture of 

 Gum-elastic Goods, by Mr. Goodyear, of New Haven, Conn., 

 the inventor and patentee, and remarked upon the changes 

 produced by the combination of a variety of inorganic sub- 

 stances, particularly the oxides of lead, &c. with this gum. 



Mr. Peale observed, that the gum, in its ordinary state, was much 

 affected by temperature, a fact familiar to every one, and was soluble 

 in some of the oils and spirits, by which its value in the arts was much 

 diminished ; the articles exhibited were free from this inconvenience, 

 retaining in the lowest temperature of the external air, all their pre- 

 sent softness and pliability. He showed, also, that the elasticity was 

 increased, and stated that they were no longer subject to the action of 

 the usual solvents of this curious substance. 



Mr. Peale directed the attention of the members to the beauty of the 

 impressions of a finely engraved copper plate, upon the sheet gum, 

 which being of uniform substance, without fibre, received the ink of 

 the most delicate lines, more distinctly and beautifully than the finest 

 paper. The samples shown were in the form of portable maps, 

 which could be put in the pocket like a handkerchief. 



Fancy table covers, ornamented with silver and gold, bronze, some 

 of which had been bleached, and others left of the natural colour, to- 

 gether with crumb cloths, bathing mats, &c. were also shown. 



Mr. Peale also mentioned, that the articles presented, were a few 

 of the many useful and fanciful applications which the ingenious in- 

 ventor had made by his improved process, and that the manufac- 

 turers were now principally employed in the production of articles of 

 necessity and utility. 



Professor Henry presented a paper, by Capt. Stockton, de- 

 tailing experiments upon the bursting of cannon. The result 

 of the experiments was, that the gun is not more liable to 

 burst when there is an air space between the powder and 

 ball, than when the wad is rammed home. 



The communication gave rise to observations from Dr. Pat- 

 terson, Prof Henry, Mr. Ord, Prof. Frazer and Dr. Bache. 



Professor Henry asked for information in regard to the ex- 



VOL. IV. — 2 F 



