Gun Cotton

l.xponments uro mailing in mnny places on rlienewly iscovered mode of preparirnj collot) as a substiiute for yunpowder. Mr. E. G. Disnnyers givea in lite Detroit Advcrtiser the ibilowiiiij account of lus experimenis : ' The "gun cotion " having been prepored, wo were anxious to try its propulsive force. Accordinglyj having procured a rifle, in oompany with two other gentlemen, we proceeded to a spot favorable for the experiment. Á mark was first stt up at the distance of 200 feet, and the rifle loaded with ten grs. of the cotton, and a ball weighing oz. 15 grs. The ball was propeüed with accuracy, and penetratedihe fence. The rifle was nextcharged with 20 grs. of the cotton, hen, upon being discharged, it recoiled with somo force; the ball was propelled with accuracy, penetrated tho fence, and came in contact with a pinc post, 4 inches thick, at 12" feet distancé from the fencc, which it also perforate'd and was lost; thus penetrating 5 inches of thicknessof pine wood. The mark was nexi sst up at 350 fet distance, and the rifle loaded with 20 grs. of cotlon ; tlje ball penetrated the fence, (one inch thick) came in contact with another, which was at right angles to the forrnor, and peneIrato.d it complelely, although it had struckft at a very acute angfe, and consequentïy perforated it very oblíqueíy - Our cotton being consumed, we had to discontinue our expenments."Silent cnrringe wheels have been introduced in London, The lire of ihe wlieel coii5'sts f an elastic tubular ring of caoutebpuo enclsed in a leather cnseT nnd ipflled wilb Ür to any degreeof lightness desired. ïh,e notiop pf the corriage is eceedingly eay.