774 REPORT — 1881. 



In conclusion I may observe that we can scarcely aufSciently admire th& 

 profound investigations which have revealed to us the strict dynamical relation 

 of heat and electricity to outward mechanical motion. It would be a delicate task 

 to apportion praise amongst those whose labours have contributed, in various 

 degrees, to our present knowledge, but I shall do no injustice in saying that of 

 those who have expounded the modern doctrine of energy, in special relation to 

 mechanical practice, the names of Joule, Clausius, Rankine, and "William Thompson 

 will always be conspicuous. But up to this time our knowledge of energy is almost 

 confined to its inorganic aspect. Of its physiological action we remain in deep igno- 

 rance, and as we may expect to derive much valuable guidance from a knowledge 

 of Nature's methods of dealing with energy in her wondrous mechanisms, it is to be 

 hoped that futm-e research will be directed to the elucidation of that branch of 

 science which as yet has not even a name, but which I may provisionally term. 

 ' Animal Energetics.' 



The following Paper was read : — 



Ohservations on the Lnprovements of the Mississippi River, and on the pro- 

 posed Ship Bailwaij across the Isthmus of Tehuantepec, Mexico. By 

 Captain J. B. Eads, G.E. 



FRIDAY, SEPTEMBER 2. 

 The following Papers were read : — 



1. Some of the Developments of Mechanical Engineering during the last half- 

 century. By Sir F. J. Bramwell, M.I.G.E., F.E.S. — See Reports^ 

 p. 494. 



2. On the Automatic Sounder, By James Dillon, M.I.C.E. 



In this paper the author pointed out the difficulties and delays that have now to 

 be encountered when endeavouring accurately to prepare soimdings and sections of 

 the beds of rivers, lakes, harbours, and sea-shores, or when determining the levels 

 or depths of existing or proposed excavations under water, and excavations and 

 dredging operations when in progi-ess, and lastly the difficulty in accurately ascer- 

 taining the character of the ground under water, before designing large hydi-aulic 

 works, &c. 



The author pointed out how he successfidly overcame these various difficulties 

 by inventing the ' Automatic Sounder.' Its construction is simple, and with it can 

 be successfully performed the diflerent operations referred to, with greater accuracy 

 and at a much less expenditiu-e of time and money, the author having tested and 

 proved its value on very extensive hydraulic and river conservancy works. 



The following is the author's description of this machine : — 



There is placed across a boat, barge, or other floating substance, near stern or 

 elsevs-here, a metal or other axle-bar, called the ' central axle,' ^\•ith its ends pro- 

 jecting a few inches over sides of boat, working freely m axle-boxes attached to 

 sides of the boat. 



Twelve or more feet (according to maximum soundings required) of a metal or 

 other bar called the ' sounding bar,' is attached to the ' central axle,' the former 

 hanging vertically in the water. The end of the central axle is passed through a 

 semicii-cular dial resting on or near the side of the boat, the sounding bar swing- 

 ing in a plane parallel to the dial and keel of the boat. 



