TO MOSES POOLE, of Searle-street, Gent., for improvements in the elastic ribs, sticks, and fillets used in the manufacture of umbrellas and parasols, and various other articles, in substitution of whalebone and steel heretofore employed, -being a communication.-[Sealed 27th November, 1852.] THIS invention consists in making parts of umbrellas and parasols, also whips, sticks, and the elastic springs of corsets and other parts of dresses, and other articles, by employing a composition, consisting of India-rubber (and combined or not with other matters), and sulphur heated to a high degree of temperature, producing an elastic horn-like substance, which, being made into like forms or shapes to those heretofore made of whalebone or steel, may be employed in the class of manufactures mentioned.

The composition employed for making the several parts of the articles of manufacture above mentioned, consists of two parts, by weight, of India-rubber (caoutchouc) and one part, by weight, of sulphur; and, although foreign matters may be used in the compound, particularly in the sticks of umbrellas and parasols, and the handles of whips, where so much flexibility and elasticity are not required, yet it is believed that foreign matters employed in such compound, tend to reduce the elasticity which results from the use of India-rubber and sulphur alone. The matters are to be very intimately blended by masticating or kneading; and, when used for the sticks of umbrellas, parasols, or the handles of whips, the same may be solid or hollow; and, if hollow, they are most conveniently made from the compound rolled into a sheet and cemented into a tubular form, before subjecting the same to the process of heat to produce the change necessary for converting the compound into the elastic condition desired; or, if the sticks of umbrellas, parasols, and handles of whips, are intended to be solid, a sheet, of the desired thickness of the compound, may be first subjected to heat, and changed into the desired character of substance, which may then be cut into fillets of the desired length, and which may afterwards be cut or rasped into the desired cylindrical or tapering forms required.

In making the ribs of umbrellas and parasols, sheets of the composition are first rolled out and subjected to heat, to convert them into the hard elastic substances before mentioned; and narrow fillets are then to be cut off and shaped into the desired form for the intended strips, fillets, or ribs, and offering a greater or less substance and elastic force, according as

they are to be used in parasols, or for larger or smaller umbrellas, or other uses; and such ribs may be scraped and polished, according as it is desired to give more or less finish to such articles.

In making springs for corsets, dresses, or other articles, it is preferred to form the compound into sheets, of a thickness depending on the substance and strength desired to be given to the springs to be cut therefrom; and having subjected the sheets to the process of heat, they are converted into the desired hard elastic substance: the forms of the springs required are then to be cut and shaped as if whalebone were being used; and it should be stated, that in cases of "busks" and other shaped springs, whether for corsets, dresses, or other uses, where it is desired that the normal state of the spring should be other than flat, the sheets of the composition are to be cut before being subjected to heat, and the portion suitable for a spring or springs should then be placed between metal (or other surfaces which will transmit the heat) of the shape desired, so that the composition may be held to the desired form when undergoing the process of heat, to convert the compound into the hard and elastic state necessary to render it suitable for springs.

In order to obtain the best elastic property to the compound above mentioned, it is found that the articles, above described, should be subjected to heat for about six hours; such heat being raised slowly up to 230° Fahr., say, in about half an hour, retaining that heat for about 1 hours, and raising it gradually during the remainder of the six hours, up to 295 or 305°-this heat may be applied in any convenient manner. It is found convenient, in thus subjecting sheets of the compound to heat, to place each of them between two sheets of iron or glass, and to immerse them in an oil bath and lard oil, which is found to be the best oil for this purpose. Sheets, thus prepared, may, when heated to about 210° Fahr., be rolled between smooth hard rollers, and by such means extended, when they may be shaped by pressing in dies; and, when desired, such dies may be engraved, and they will produce impressions on the materials.

The patentee claims the manufacture of elastic ribs, sticks, and fillets, used in the manufacture of umbrellas and parasols, and various other articles, (in substitution of whalebone and steel, heretofore employed) from hard and elastic substances, produced by combining India-rubber and sulphur, and subjecting the same to the requisite heat.

The following paper, by Mr. C. WILLIAM SIEMENS, of London, was read:-"On an improved governor for steam-engines.”

The governor of a steam-engine has for its function to administer the supply of steam to the working cylinder in the ratio of the changeable load against the piston,-the purpose of which is to obtain an uniform velocity in the engine. In imparting motion to manufacturing machinery, the greatest possible regularity is required; for a regular motion enables the manufacturer to work his machines at the highest speed consistent with safety; produces the largest quantity and a uniform quality of goods; saves in personal attendance upon the machines; and, lastly, increases the durability of the entire mechanism employed by preventing back-lashes and jerks.

The common (Watt's centrifugal) governor is notoriously imperfect in its action, being defective in principle in two respects. 1st-It cannot regulate, but only moderates the velocity of the engine: that is, it cannot prevent a permanent change in the velocity of the engine when a permanent change is made in the load upon the engine; and it can only moderate the extent of permanent change in velocity, because its influence upon the throttle-valve depends on a change in the angular position of its weighted levers or pendulums, which change can only be effected by a permanent increase or decrease of the engine's velocity.

2nd-It cannot commence to act upon the valve until after the engine has undergone already a considerable change in its velocity; for at the instant when a portion of the duty is thrown on or off, the weighted levers are still in a state of equilibrium, and it is only by an accumulation of the fault, that they acquire a power to overcome the friction of the valve. To check the effect of the loss of time before the governor begins to act on the engine, it then moves the valve to the opposite extreme; and a series of fluctuations will follow before the engine can recover a steady velocity.

The author, in pointing out these defects in Watt's governor, referred to a diagram which shewed the two extreme positions of the weighted levers when in regular work; the one to be at an angle of 25°, and the other at 35° from the axis. The corresponding extremes of velocity were inversely as cos. 25° to

cos. 35°, or as 905 to 952. The regular speed of the engine must, therefore, undergo a periodical change of 5 per cent., supposing the pendulums to be suspended from a point in the axis of rotation. But if, as is most frequently the case, they are suspended from points removed some distance laterally from the axis, the change of speed is nearly doubled. The fluctuations which follow a sudden change of load, will, however, far exceed those limits. Let it be imagined that the engine is working at its medium speed, and that the governor balls are revolving in equilibrium. Suppose a string to be tied between the two balls, of tensile strength equal to the resistance of the motion of the throttle valve. Let a portion of the load be thrown off the engine, and the velocity of its fly-wheel and of the governor balls will gradually increase; but no alteration in the angular position of the balls can take place until their increase of centrifugal force suffices to break the string. The velocity will at this moment be proportionate to a much higher position of the levers than the adjustment of the valve requires; they will, however, ascend into that position, and remain until the velocity of the engine has dropped sufficiently below its proper speed to accumulate acting power in the governor in the opposite direction.

In practice, the defects of the governor are ameliorated by personal attendance to the engine at the times when considerable changes in its load are expected to take place. In cotton and flour mills, for instance, the attendant on the engine is always forewarned of such changes by a bell, and effects the adjustment of the valve by hand.

Since the time of Watt, many attempts have been made to produce a more perfect governor. Amongst them the governor of Hick is the most remarkable, the regulating power of which depends on the rapidly increasing resistance, at increasing speeds, of the atmospheric air against rotating wings.

The two wings of Mr. Hick's governor are mounted upon a heavy boss, containing a female screw, which is made to slide freely upon the threads of an upright male screw. Rotary motion being imparted to the latter by the engine, the wings will partake of the same until the resistance of the atmosphere against them equals the tendency of their entire weight to slide down upon the inclined threads of the screw. If the engine exceeds that velocity, the wings will rise and thereby shut the valve, and vice versa.

It is apparent that it makes no difference to the speed of the wings, and consequently of the engine, whether the former are in a more or less elevated position; and it follows, therefore, that this governor is free from the first-named objection to Watt's governor. It partakes, however, of the second, inasmuch as the resistance of the atmosphere is generally in equilibrium with the weight upon the inclined planes of the screw; and before either the one or the other can preponderate sufficiently to overcome

the resistance of the throttle-valve, it is necessary for the engine to deviate sensibly from its regular speed.

The author then described another variety of Mr. Hick's governor, which is remarkable for its simplicity and sensitiveness, although evidently less powerful than the former. The wings in this case were made to revolve by the preponderance of one loose weight over another; the engine being constantly at work to raise the heavier weight. Either of the loose weights was connected to the throttle-valve spindle; so that the tendency of the heavier weight was to open the valve, while the engine was ever busy to close it.

Another form of Hick's governor was proposed a few years since, in which the wings themselves were shaped like portions of screws; and being free to slide upon straight keys on the driving-shaft, were required to balance their weight by rotating under water, and so constantly tended to screw themselves upwards in the water.

The pneumatic or cataract governors, are a distinct group, of which a great variety have been proposed from time to time. The earliest is the cataract of the Cornish engine, by Watt. Heinrick's bellows governor, Lariviere's and Pritchard's hydraulic governors, are other varieties, which can readily be described under one head, as they differ only in details. A pump is worked by the engine to force water or air below the weighted piston of a second cylinder or cataract, from whence it again escapes through a contracted aperture in a uniform stream. If the engine pumps more water than is discharged by that aperture, the weighted piston will rise and close the throttle-valve by means of a lever; if, on the other hand, it pumps less than the discharge amounts to, the weighted piston will sink and open the valve. Abstracting the differences in the height of water column above the discharge pipe, and the friction of piston, the hydraulic governor would be capable of effecting the complete adjustment of the valve. It may moreover be made sufficiently sensitive for ordinary purposes, by adopting a comparatively large supply pump. It is, however, very liable to derangement, owing to the valves and pistons employed, which, if they become leaky or stiff, will greatly affect the speed of the engine, and necessitate frequent re-adjustment of the discharge orifice, according to the judgment of the attendant.

The author next proceeded to describe his "chronometric governor," which is dissimilar in principle to any above referred to.

The chronometric governor originally consisted of two essential parts, namely, the chronometer, and the differential motion between the chronometer and the engine, by which the effect upon the valve was produced.

The differential motion was obtained by means of three bevil wheels, one of which was turned by the engine; the opposite one by the chronometer in the opposite direction, and the re2 L

VOL, XLIII,