54 ANNUAL OF SCIENTIFIC DISCOVERY. 



selves to the wreck. The iron, by the action of the sea-water, was nearly 

 worthless. The arrangement of the submarine apparatus employed was 

 so perfect, that no accident of any description, occurred to any of the 

 divers during the prosecution of the work, the men frequently remaining 

 under water for twelve hours. 



ON THE CONSTRUCTION OF WATER-METERS. 



The following paper on the theory and construction of water-meters, 

 was recently presented to the Society of Arts, London, by Mr. J. Glynn, 

 P. R. S. After alluding to the necessity for some correct measurer of 

 water, now that there was a very general demand for the constant supply 

 system, the author described what he thought were the essentials of a good 

 water-meter. These were, 1. That it should correctly measure and show 

 the quantity of water delivered under varying heads or pressures ; 2. That 

 it should not be liable to get out of order ; 3. That it should be easily 

 cleaned, oiled, or adjusted ; and 4. That the cost be not too great, so that 

 it may be generally used by householders. The majority of those hitherto 

 invented had, he considered, been deficient in one or more of these essen- 

 tials, and the Jury of the Great Exhibition did not award even honorable 

 mention to any meter, though five different contrivances were exhibited 

 there. He then explained the leading features of the several plans which 

 had been proposed, commencing with the double cistern, to be emptied and 

 filled by turns, the contents of which being known, and the ebb and flow 

 of the water registered, a very simple and compact meter for water delivered 

 in large quantities, at a low pressure, might thus be made. The same idea 

 of twin vessels and a reciprocating action by means of a diaphragm, or 

 flexible partition, had been further elaborated, something like the gas meter 

 upon that principle. The reciprocating motion of a piston in a cylinder 

 like that of a steam-engine had also been proposed, but some head of water 

 was required to overcome the friction of the mechanism in this case. Other 

 forms of the steam-engine had also been suggested, such as the disc-engine, 

 which combined the rotary with the reciprocating action. The water- 

 wheel on a small scale, and revolving in a circular case, had been tried in 

 various ways, and was a favorite scheme, but not a successful one. The 

 clepsydra, or water-clock, had also been tried to measure water ; and after 

 this came drums of many shapes, some receiving the water at their centre, 

 others at their circumference. Of those taking the water at the centre, 

 some resembled a fan blast, some were like Appold's pump, and one was 

 like Barker's mill, which had ingenious contrivances for obviating friction, 

 for continual lubrication, for straining the water as it entered, and for pre- 

 venting acceleration of the drum or mill part of the machine, for which 

 Mr. Siemens had a patent. Another type was the insertion in a pipe of 

 something like a screw-propeller, which would register at the rate at which 

 the water flowed past ; and there were modifications of it in portions of 

 screws, drums with spiral vanes, and so forth. Mr. Siemens had a patent 



