at any required angle ; and the rope being wound round it, was expected to be delivered more freely, and with less risk of breaking, than by the usual mode. Experiments made at Cromer confirmed the anticipations of the inventor, and the apparatus has now been in use for three years, and, apparently, has given much satisfaction.
Finally, Mr. Thorold has given to Mr. Hase's reel a stronger and more com pact form, has both expedited and facilitated the coiling of the rope evenly upon it, and has placed the mortar and reel upon wheels, so that it may be trans ported expeditiously to any place where it is wanted. It is obvious, however, that by so doing, the expense of the whole apparatus is greatly increased ; that it is now scarcely capable of being conveyed by hand, as Capt. Manby's, and even Mr. Hase's is ; and that, therefore, situations may occur, to which it would be difficult, if not impossible, to bring it. The following figure presents a side elevation of the cart (with the near wheel off) and reel, and the mortar elevated into a position for firing. The axis of the conical reel is fixed in the centre of a strong wooden cross, which is framed and secured by four bolts to the bars b b ; these are hinged at c to the cart; d is a bar of iron with holes, serving as an elevator ; it is screwed on to the frame b, and one of the holes being placed on a pin fixed in the cart's side, retains the reel at the required angle. Two chairs e a are fixed on at each sine of the cart, and to the frame b b, which retains it ; while the reel is vertical, the elevator d catches the pin by its last hole. At f there is a movable ring and winch handle (not represented); g a guide bar, turning on pivots in the frame b, on which is a sliding box h, to be used in coiling the rope. Within the winch ring is a hook ; a bend of the line
being placed on this, the reel is turned once round, and the rope passed through the eye of the guide box h, properly constructed, and a pair of nippers (not shown). When the mortar is to be fired, the guide bar g is thrown back into the position represented, and the winch. The pressure of the guide bar being thus taken off, the elasticity of the cord causes it to rise a little, and throw off two or three of the upper coils; the next coil is kept in its place by one of the assistants laying his finger on it, and not withdrawing it until the moment of firing. The mortar is to be placed a few yards to leeward of the reel, with the line attached to the shot. - A clamp n hangs from the frame b, by means of which the last coil of the rope is to be bound to the rim of the cone, in order to secure it for travelling, the remainder of the line being on the frame o o. Another line, on a similar frame, is stowed in the tail of the cart; and in front of the axletree there is a locker for the shot, the peculiar form of which is shown by the separate figure q. The time required for winding the line, and firing the shot, is one minute and a half. Numerous certificates on the advan tages of Mr. Thorold's apparatus, accompanied that gentleman's communication to the Society of Arts, who voted him the silver Vulcan medal :—a model of which invention is placed in the Society's Repository.