386 



THE CIVIL ENGINEER AND ARCHITECTS JOURNAL. 



[Dec. 



tlier, tlie f wo ends of the outer spring are made to come at the opposite side 

 of the piston to the two ends of the inner spring. The outer spring a is 

 formed witli an inner flange, and the inner spring b comes hitween the 

 flanges, and causes hy its elastic force, to open out and press tlje top and 

 bottom surfaces of the outer spring a, against the top and bottom plates of 

 the piston. As the two springs require to be compressed when the piston 

 is introduced into the cylinder, they will when in exert an expansive force 

 and fill up the cylinder in which it is working, notwithstanding any wear 

 either in the cylinder or the packing. 



The claim is for parking of pistons by the use of helical springs a in 

 combination with spring 4. 



M.\RINE ELECTRIC TELEGR.VPH. 



Arthi'r Philip Perceval, of East Horsley, Surrey, Clerk, for " Im- 

 provements incommunicatiti!; Iietwcen places scpiiratcd bij water," — Granted 

 April 23; Enrolled October 2», 1S4C. 



These improvements consist — First, when the electric wires have been 

 eflectually secured from water, by tlireail and gum or caoutchouc, they are 

 to be cncloserl in a *' necklace of iron rings in conlact with each other, or 

 of iron sockets dove-tailing one into the other. Ciiil it on the deck like 

 any other cable, and throw it overboard in transit." Secondly, where 

 this means of communication is unavailable, transfer a semaphore appa- 

 ratus on land, to hulls, fixed at proper distances and secured by an- 

 chors, sufficiently spacious for the accommodation of men to work the 

 signals. 



AMERICAN PATENTS. 

 Granted in August, 1845, reported in the American Franklin Journal. 



For "«tt Improved metliod of making matrices for casting printers' tijpe.' 

 Thos. W. Starr, Philadelphia. ' 



This is for forming matrices on types by the electrotype process, which 

 afterwards are properly fitted up to give the necessary strength and dura- 

 bility. Claim. — " Having thus fully described my method of forming 

 matrices for casting the face of printers' type, and other articles therein, 

 what I claim as new, and desire to secure by letters patent, is the manner 

 of forming the same by means of a common type or cut, and a metallic plate 

 with an opening, with slanting sides, the two arranged and prepared in the 

 manner described, and placed in a solution of sulphate of copper, and 

 connected with the pule of a galvanic battery, in the same manner usually 

 practised in electrotyping ; and after receiving a sufKcieut deposit of cop- 

 per, to he fiUed up for use, in the manner set forth." 



For " nil Improved method of lessening friction in clocks, 6-c. Eli Terry, 

 Plymouth, Connecticut. 



The claim is for " the employment of a suspension piece, arranged and 

 operating substantially in the manner of that which I have denominated 

 the friction-prevenior, for sustaining the weight of the balance wheel and 

 its arbor. The arbor of the balance wheel is supported by a stirrup which 

 Tibrates as the balance rotates, so as to relieve the journals or pivots from 

 the friction due to the weight of the balance." 



YoT " a composition of matter for removing acids from cloth, Ifc . Solo- 

 mon Guess, Boston. 



This compound consists of 4 lb. of fucus vesiculosus (sea or bladder 

 wrack) boiled in 3 pints of water until reduced to one, mixed with one 

 quart ox gall, 1 lb. of carbonate of ammonia, j lb. of alum, and 24 lb. of 

 common white soap ; the whole is properly melted and mixed together. 



For "<m Improvement in the propeller." John Ericsson, New York 

 City, N. V. 



The claim is for constructing the hub with perforated projections, and 

 the combination of the same with elliptic braces, for the purpose of sus- 

 taining and strengthening spiral propeller blades. The projections from 

 the hub to which the blades are attached are made hollow for the passage 

 of the water in the direction of the plane of the face to which the bladels 

 attached. And the elliptic braces are segments of hoops made oblique to 

 the axis, and therefore elliptical— they are used to brace together the 

 blades about midway between the hub and tips. 



machine for folding sheet metal. Henry A.jRoe, Erie, Pennsylvania. 

 The patentee says :— "The nature of my invention consists, first, in at- 

 taching what I term the folding plate, that is to say, a plate which gripes 



the edge of the sheet of metal, and on which the folding is elTected by the 

 folder, to a bed placed below it and hinged to the bed of the machine, so 

 that the sheet of metal can be folded entirely over, instead of griping the 

 sheet b> a square jaw extending above and forming a stock above the 

 plane of the bed of the machine, as heretofore, which prevents the sheet 

 from being folded entirely over, and therefore requiring a secondary opera- 

 tion to complete the folds. Secondly : la sup|)orting the said folding bed, 

 to which the folding plate is attached, in the middle of its length by ajoint 

 bolt, the head of which lies in a semicircular recess in the folding bed and 

 as near as practicable in a line with the axis of motion, and secured in the 

 bed of the machine. Thirdly ; In the employmtut of a side plate below 

 the folding bed and back of its journals, provided with inclined planes oa 

 which j)rojectious from the back of the folding bed rest, so that by the 

 working of the side plate by a lever at the end of the machine, the folding 

 plate can be made to gripe and liberate the sheet of metal." 



For "an Improvement in the propeller. Leonard Phleger, Wilmington, 

 Delaware. 



The invention consists in making the wings of the propeller in the pre- 

 cise form of such a portion of the convex surface of a regular cone as 

 would be cut out by a plane or planes passing through its axis, and com- 

 prehending about half of its surface, each wing being attached, along one 

 of its straight edges, to the shaft. 



GUN COTTOX. 



It will be remembered that Dr. Otto, of Brunswick, claims to be con- 

 sidered one of the inventors of gun cotton, and states that he was led to the 

 discovery by a remark published by Pelouze, in the Journal de Chemie. M. 

 Pelouze, at the Academy, on the 2nd November, says, on the subject of gun- 

 cotton: "Although M. Schonbein has not published the nature or mode of 

 preparation of his cotton, it is evident that the properties which he assigns 

 to it can only apply to xyloidine. Reasoning on the hypothesis that the 

 poudre-coton is nothing else than xyloidine, I may be permitted to say a few 

 words with respect to its history, and of some of its properties. Xyloidine 

 was discovered in 1833 by M. IJraconnet, of Nancy. He prepared it by dis- 

 solving starch and some other organic substances in nitric acid, and precipi- 

 tating these solutions in water. In a note inserted in the Comptes remlus 

 de V Academic ties Sciences, in 1 838, I showed that the xyloidine resulted 

 from the union of the elements of the nitric acid with those of starch, and 

 explained, by this composition, the excessive combustibility of the substance 

 produced. I ascertained — and this I think is a verv important result in the 

 history of the applications of xyloidine — that instead of preparing it by dis- 

 solving the cellulose, it might be obtained with infinitely greater facility and 

 economy by simply impregnating paper, cotton, and henip with concentrated 

 nitric acid ; and that these organic matters thus treated took fire at 180 de- 

 grees, and burnt almost without residuum, and with excessive energy: but I 

 think it right to add, that I never for an instant had an idea of their use as a 

 substitute for gunpowder. The merit of this application belongs entirely to 

 M. Schonbein. Eight years ago, however, I prepared an inflammable paper 

 by plunging into concentrated nitric acid, a sheet of paper known in com- 

 merce by the name of papier ministri. After leaving it there for twenty 

 minutes, I washed it in a large quantity of water, and dried it in a gentle 

 heat. I have recently tried this paper in a pistol, and with about three 

 grains pierced a plank two centimetres in thickness (about three quarters of 

 an inch), at a distance of twenty-five metres." The results of experiments at 

 Paris, under authority, were communicated to the Academy on the 9th inst. 

 The proved advantages of the gun-cotton appear to he, cleanliness, rapid 

 combustion without solid residue, the absence of had smell, lightness, no dust 

 possible, and therefore no sifting necessary, an indisputable force, and valued 

 at present as triple that of an equal weight of gunpowder. The disadvantages 

 are — volume, and hence a difliculty in making up, and in the transport of 

 ammunition ; and the production of a large quantity ot watery vapour within 

 the guns, which is, perhaps, more inconvenient than the dirt of ordinary 

 powdrr. Of five specimens tried, one fired the fourth time without the gun 

 having been sponged, was projected with the greatest part of the cotton un- 

 burnt, and this was so moist that it would not take fire in the open air. 



Test of quality. — M. Pelouze announced an important discovery by two of 

 his laboratory pupils ; it is, that when xyloidine has reached its greatest de- 

 gree of explosive power, tli.-n it is completely soluble in ether. Hence a 

 test of quality, and a proof of the best make. 



At a meeting of the Chemical Society of London, the same day, a paper 

 was read On (Ac Gun Cotton, by Mr. E. F. Tesciiemachkr. The author 

 stated that he entered on this subject with a view of obtaining some data 

 as to how far the possible introrluction of this substance in the place of 

 gunpowder was likely to affect the consumption of saltpetre and uilrale of 

 soda. The gun cotton examined was made by Mr. Taylor's process. 

 Fifty grains of South American cotton were dried over a waterbalh, and 

 lost 3-40 grains. It was steeped in the mixed acids, washed, dried, and 

 found to have increased to 79 grains. The acids used were then examined, 

 by saturating with carbonate of soda, and it was found that the cotton had 

 taken acid equivalent to 2bi grains of soda ; or 48 grains of dry nitric acid 



