IS-li.-] 



THE CIVIL ENGINEER AND ARCHITECT'S JOURNAL. 



55 



AN IMPROVED WATER METER. 



Invented by Mr. Alexander Mitcheli, Watch & Clock Maker, Glasgow; described by James Thomson', Esq., F.R.S.E., M.R.I. A., F.R..S.S.A., 



Civil Engineer, Glasgow. 



(Bead before the Royal Scottish Society, 12th Decemhef, 1842, and reported in their Transactions.) 



The action of the meter, referring to the 

 annexed figure, may be described as folio, -vs: — 



The supply-pipe// being connected to the 

 water main by a coupling, &c., in the usual 

 wwy, the water flows through the valve g, and 

 passing into the cylinder h h h h at j, is dis- 

 charged by the pipe k into the receiving cis- 

 tern 1 1, from which the water is drawn off by 

 a stop-cock I', 



Upon one end of the axis or spindle of the 

 screw a a is fitted a pinion d, working into the 

 train of wheels e e c e, so arranged as to indi- 

 cate the quantities of water discharged either 

 in gallons or cubic feet, similar to the index of 

 gas meters — the whole being set in motion by 

 the flow of water through the cylinder acting 

 upon and causing to revolve the Archimedean 

 screw enclosed within it. To prevent the 

 screw from being driven forward by the water, 

 and in order to reduce the friction to a mini- 

 mum, the end of the axis at d has a hard steel 

 point inserted, which works in a cock or pot- 

 lance fitted outside, and enclosed in an oil box, 

 supplied with oil through the filter d'. 



In order to render the indications of the 

 meter uiiiformlv correct, under different heads 

 or pressures of water, the following very inge- 

 genious method of adjustment is adopted: — 

 Upon the axis of the screw are fixed four thin 

 brass wings or leaves c c c c, each moving upon 

 a separate hinge or pivot c', fixed at right an- 

 gles to the axis, with screw nuts upon the end 

 of each pivot, by means of which the wings 

 can be maintained open or shut at pleasure, 

 and so lessen or increase the discharge of water 

 at each revolution of the screw. The lower 

 pair of wings in the drawing are represented 

 slightly open. With this power of adjustment, 

 it is very easy to regulate the quantity of water 

 discharged under different pressures, so as to 

 correspond exiictly with the index and train of 

 wheels, which can best be ascertained by trial 

 upon setting up the meter, say by a measure- 

 ment of 20 gallons, and opening or closing the 

 fly leaves, to bring the quanlity measured and 

 the index to corrcsjjond. 



It will be evident that the quantities of water 

 passing through a metre, upon this principle, 

 would be correctly indicated tloivn to thai quan- 

 tity requisite to overcome the friction of the screw, below which 

 amount, however, the water would pass through the cylinder without 

 affecting the index, and consequently without being registered. Al- 

 though the quantity thus passing would not be considerable in a well- 

 constructed meter, Mr. Mitchell has recently introduced an improve- 

 ment which completely obviates this objection, and renders the indi- 

 cations correct under any circumstances, and down to the smallest 

 quantity. 



This is accomplished by means of the conical valve cock g, which 

 is so constructed as to act instantaneously, and so keep the supply 

 either flowing at the full bore, or suddenly'shut off, when the cistern 

 is full. The opening and shutting of this' valve is effected in the fol- 

 lowing manner :— To the end of the lever A A, which works upon a 

 journal, and is raised or depressed by the ball-float /, are attached the 

 two arms ju;; and 0. As the water in the cistern rises, these arms 

 are carried forward without acting, however, upon the valve, until 

 one of the chains, connecting them with the lever and lead-weight u ii, 

 is upon the stretch. At this point the lever and weight Are upon a 

 balance, so that the least further rise of water in the cistern carries it 

 suddenly over, and allows the valve g to close. A reverse motion 

 takes place on the fall of the cistern water, the action of the other arm 

 and chain js;^ opening the valve, which a small catch retains in its 

 place ag'ainst the force of the supply water. To prevent any injury 

 to the pipes from the sudden action of the valve, an air-vessel wj is 





t= 



=ti 



=i 



Refebrnpe to Enceaving.— ABCD, outer cise of thin east iron for cnclosin;^ the apparalus shown in 

 seel inn, n a Arehimedean screw workm^ in the cyhndcr hh. cc thin br.iss wind's (ir Hies, «iili adjiistin^ 

 screws for regulating the motion of the screw, d pinion upon the end of the screvv-spindle or a\is. 

 e e f train ol wheels s^et in motion by the pinion rf, to indicate the i|uanlity passed through the cylinder, 

 closed in with a glass front. / supply pipe, g valve worked hy the lever li li, connected to the b ill- 

 Ih at i. h h lever for opening and shutting the valve g. k dischart;e pipe llowing into the cistern I I. 

 m air vessel to prevent injuring the pipe On opening and shuttiiijj of the valve, n n lever, with had to 

 retain the valve open or shut, o o and p p arms fixed upon the end ol the lever h It, and attached with 

 chains to the lead weight n. 



attached to the supply-pipe immediately above the position of the 

 valve. 



The introduction of this improvement, which prevents the possi- 

 bility of water passing unregistered through the cylinder, renders this 

 description of meter very perfect, and capable of indicating accu- 

 rately the smallest as well as the largest quantities. From the small 

 cost, too, at which they can be ni;inuf,ictured, it is to be hoped they 

 will soon be brought into general use, and sitbsliluttd for the present 

 unequal mode of water assessment upon house rent. 



Report of Committee. — Your Committee having met with Mr. 

 Mitchell, and having again heard his explanations, and carefully exa- 

 mined the water-tneter submitted to them, came to the following con- 

 clusions:— 1. That as far as they can judge, this meter m^iy be consi- 

 dered sutTicientIv accurate to form a fiir measure between water com- 



panies and their customers. 



iit its construction is simple, aud 



well devised for permanent practical use, being little subject to de 

 rangement from the wear of its parts. 3. That its rate of registra- 

 tion being susceptible of easy adjustment, either in plus or minus de- 

 gree, and its actual delivery, during certain portions of time, being 

 always ascertainable by the consumer, its use may be adopted willi 

 confidence, as being alike equitable to the suppliers and the con- 

 sumers. 



