DIVING BELL 



67 



means the attention of the operator below may bo drawn to the speaking tube when it 

 is required to converse with him from the surface of the water, and the men whose 

 duty it is to attend to tho operator below can, by placing their ear at the end of the tube, 

 hear tho bell struck below as a 

 signal for communication with 

 them at the surface. 



The only parts of the apparatus 

 not yet described are the saw for 

 cutting the tops of piles to an uni- 

 form level, the pump which enables 

 tho divers themselves to rise to the 

 surface in the event of the flexible 

 hose being detached or injured, 

 and the contrivance for screwing 

 an eye bolt into the side of the 

 sunken vessels. 



Tho arrangement of the saw- 

 frame and connections are shown 

 in Jig. 636. Only as much of the 

 bottom of the Nautilus is shown 

 as will render the position of the 

 saw understood, p is a pile which 

 is required to be cut down to the 

 same level as the others, E is the 

 blade of the saw, D the framing 

 by which it is stretched, c, D, the 

 handle which rests on the cross bar 

 K, to which is attached the up- 

 right part of the handle which is 

 laid hold of by the workman inside 

 when working the saw. H, G, F, 

 a bent lever with two friction 

 rollers at F, which guides the 

 saw forwards while making tho 

 cut. 



Tho pump for ascending in case 

 of accident to the air hose is not 

 shown in the drawing. It is a 

 simple force pump placed in the 

 working chamber, by which the 

 ballast water in vr w, fig. 630, can 

 be pumped out so as to lighten the 

 apparatus sufficiently to allow of 

 its ascent. 



The apparatus for fixing the eye bolts is shown in fig. 637. The operation of this 

 apparatus is as follows : It will be observed the chamber D opens outwards to the 

 water, so that when tho sliding partition or valve y is forced down by the lever g, the 

 communication of the water with the chamber is cut off. The lid z being removed, 

 a bolt (or other operating tool or instrument) is placed within the chamber c ;. the 

 rod K is forced through the stuffing box I until the recessed end of the rod contains 

 the end of the bolt; the small rod,; is then screwed through the stuffing box n, until 

 the screw on the end of this rod has become affixed to the end of the bolt contained 

 within the recess at p. The lid z of the chest is then fastened on, and the partition 

 or valve y raised, the stuffing box M preventing the escape of air. Communication is 

 thus opened between the chambers A and D, the latter being open outwards. The rod 

 i is now pushed outwards by pressing on the handle k through the stuffing box I, 

 until the vessel or object to be operated upon is reached, when the operation is per- 

 formed as required. It will be observed that the stuffing box prevents the escape of 

 air out of the bell or the admission of water into it, the stuffing box n having the same 

 tendency. After the operation with the tool or instrument is complete, the rod k is dis- 

 connected by unscrewing the rod,;, and is drawn into the chamber A. by means of the 

 handle k ; the partition or valve y is again lowered, and the operations above described 

 are repeated. It will hence be obvious that a number of eye bolts might in this manner 

 be successfully inserted in the side of a sunken vessel from the diving bell, so that by 

 hooking on the ' camels ' the strain would be so distributed as to prevent injury by the 

 process of lifting the said vessel. 



