229, REPORT—1874. 
which the gut-band is attached to a weight of fixed amount, which, when no water 
is passing, maintains the disk at the top of the cone. i 
ater being catised to How through the cone, the disk will obviously move to a 
level at which the counterbalance weight is exactly balanced by the excess of pres- 
sure of the water on the upper surface of the disk, added to the weight of the disk 
in water and of the guide-wheels and wire in air. 
There is therefore for every particular velocity of water a particular position of 
the disk from which it will not move until that velocity is changed. The particular 
rate in gallons per hour for each particular position of the disk had been deter- 
mined, and a scale had been constructed on which a pencil, attached to the cross- 
head carrying the guide-wheels, shows at any instant the rate of flow in gallons per 
hour, In practice this scale is printed on a sheet of paper, which is mounted on a 
drum and caused to revolve once in 24hours. By this means the rate of consunip- 
tion in the district for every instant during the day and night is determined ; and the 
waste of water is distinguished from the use of water by the comparatively steady 
nature of the line due to the latter. By placing a turning key on the plug of the 
stopcock outside any private premises during the night, and by applying the ear 
to the top of the key, any flow of water may be detected. If waste is thus found 
to be talatig place the stopcock is closed. 
The waste of a district is thus traced to a few premises, and on the followin 
morning the diagram is found to have recorded the change of rate in the flow causec 
by the closing of each stopeock, and the degree in which the subsequent repairs 
should redtice the consumption. 
The author concluded by stating that waste-water meters had been for somé time 
in successful operationin Liverpool, where, until their application, the town was on 
intermittent supply at the rate of about twenty-five gall ons pet head per day for 
domestic purposes, which was found to rise above thirty-three gallons per head 
during an experimental constant supply. 
Waste-water meters had, however, been applied in thirty-six districts, containing 
in the aggregate 89,502 persons, and the domestic consumption had been thereby 
reduced to 16-9 gallons per head per day, at a trifling cost and with but little 
annoyance to the people. 
The systeni was being qiiickly extended to the whole district of supply. 
On a new Method of Isometrical Drawing*. By Guorek Faweus. 
On Coal Mining in Italy. By P. tz Nuvez Foster, jun. 
On a New Form of Screw-Lowering Apparatus. 
By EH. J. Harwanp. 
The author, with the aid of models, gave a detailed description vivd voce of a 
screw-lowering apparatus for ships which he had lately invented. He said that in 
some voyages, and especially during those across the Atlantic, the wave-line on the 
side of the ship was very often such as to leave the ordinary screw half exposed. 
Under these circumstances the engines had only half the work to do, and conse- 
quently were apt to run off at such speed as to injure the machinery. The conse- 
quence was that the engineer had to throttle or cut off a considerable portion of the 
steam, and the speed of the vessel was much reduced. To obviate that, a plan for 
lowering the screw was being introduced, which enabled the engineer in heav 
weather to keep the vessel going much steadier, with practically very little reduced 
speed. A large amount of useful power was thus utilized, with the advantage of 
uniform motion. 
Instead of the engineer being obliged at different parts of the day to slow the 
engines, he was independent of the weather, which became merely a matter for the 
* Printed ¢ extenso in‘ The Engineer,’ vol. xxxviii. p. 192. 
Tt Printed im extenso in,‘ Engineering,’ vol. xviii. p. 311. 
ie = Oe 
