128 DIVING BELL. 



the surface, and thus cutting oft' the communication with the external air", 

 A peculiar sensation is perceived in the ears; it is not, however, painful. 

 The attention is soon directed to another object. The air rushing in 

 through the valves at the top of the bell, overflows and escapes with a 

 considerable bubbling noise under the sides. The motion of the bell 

 proceeds slowly and almost imperceptibly, and on looking at the glass 

 lenses close to the head, when the top of the machine just reaches the 

 surface of the water, it may be perceived by means of the little impurities 

 which float about it, flowing into the recesses containing the glasses. A 

 pain now begins to be felt in the ears, arising from the increased external 

 pressure ; this may sometimes be removed by the act of yawning or by 

 closing the nostrils and mouth, and by attempting to force air through 

 the ears. As soon as the equilibrium is established the pain ceases; but 

 recommences almost immediately by the continuance of the descent. 

 On returning, the same sensation of pain is felt in the ears, but it now 

 arises from the dense air which had filled them endeavouring, as the 

 pressure is removed, to force its way out." 



" If the water is clear and not much disturbed, the light in the bell is 

 very considerable, and even at the depth of twenty feet was more than 

 usual in many sitting rooms. Within the distance of eight or ten feet 

 the stones at the bottom began to be visible. 



" The pain in the ears still continued at intervals, until the descent of 

 the bell terminated by its resting on the ground. 



Signals are communicated by the workmen in the bell to those above, 

 by striking against the side of the bell with a hammer. Those most 

 frequently wanted, are indicated by the fewest number of blows ; thus a 

 single stroke is to require more air. The sound is heard very distinctly 

 by those above." 



Another method adopted of divers reaching vessels to fasten tackling 

 to weigh the sunken mass, by means of buoys formed of copper, air 

 tight, is by being clothed in a water proof diving dress, by which means 

 they can delfcend to any required depth and rise at pleasure. 



Many of the guns (two of which, of large calibre, are shown to visitors 

 of the Tower of London), stores, &c. of the Royal George, which sunk at 

 Spithead on the 29th of August, 1782, have been recovered by means of 

 the diving bell, in which men can work with equal facility at almost any 

 depth in water, as upon the surface of the earth. 



Notwithstanding these attempts to lighten the wreck of the Royal 

 George, in the hope of raising her by means of copper cylinders air tight, 

 yet they were only partially successful, and the great obstruction caused 



