The apparatus consists of
Air-pump.—This improved air-pump consists of two double action cylinders, each cylinder capable of supplying about 135 cubic inches per revolution. The advantage of this air-pump is, that it can supply air to two divers, working independently and at different levels, each diver being in direct connection with one of the cylinders. The air-pipes are in lengths of 45 feet and 30 feet, made of vulcanised india-rubber with a galvanised iron wire imbedded; this protects from corrosion, and allows the air to pass through the pipes with less friction.
Diving Dress.—The diving dress is made of solid sheet india-rubber, covered on both sides with tanned twill; it has a double collar, the inner one to pull up round the neck, and the outer one of vulcanised india-rubber to go over the breast-plate and form a water-tight joint. The cuffs are also of vulcanised india-rubber, and fit tightly round the wrist, making, when secured by the vulcanised india-rubber rings, a water-tight joint, at the same time leaving the diver's hand free.
Breast-plate.—The breast-plate is made of tinned copper, and has a valve in front, by which the diver can regulate the pressure of air inside his dress and helmet. The outer edge of the breast-plate is of brass, and is secured by screws to the outer collar of the dress.
Helmet.—The helmet is made of tinned copper, and has a segment bayonet screw at the neck, corresponding to that of the breast-plate, which enables the helmet to be removed from the breast-plate by one-eighth of a turn. It has three strong plate glasses in brass frames, protected by guards; two oval at sides, and a round one on the front; the front one can be unscrewed, to enable the diver to give and take orders. At the side is an outlet valve, which, by inserting a finger, the diver can close, and so rise to the surface. The valve allows the foul air to escape, and prevents the entrance of the water. An elbow tube is securely fitted on the helmet, to which is fixed an inlet valve, to which the air-pipe is attached. The inlet valve is made that the air can enter, but in case of a break in the air-pipe it cannot escape.
The front and back weights are of lead, heart-shaped, and weigh about 40 lbs. each.
Boots.—The boots are made of stout leather, with leaden soles, and are secured over the instep by a couple of buckles and straps. Each boot should weigh at least 20 lbs.
Crinoline.—The crinoline or shackle is used for deep water; it is placed round the body and tied in the front of the stomach: being supported by braces, it affords protection to the stomach, and enables the diver to breathe more freely.