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 Read he/ore Section, G, British Aswcta tion,, Tomnto, 1897. 
 
 ^anadiaii ^ocklij of ^m\ ^itgiiiecns. 
 INCORPORATED 1887. 
 ADVANCE PROOF— ('S«&i««;' to revision) 
 
 N.B.— This Society, as a body, does not hold itself responsible for the fact§ 
 and opinions stated in any of its publications. 
 
 HYDBAULIC LABORATORY, McGILL UNIVERSITY. 
 
 By Henry T. Bovey, M.Inst.C.E., LL.D., etc., and 
 
 ''j. T. Faemeb, Ma.E. 
 
 (To be read Thursday, May 5, 1898 ) 
 
 General Description.— Tho laboratory is 39 feet in length and 31 
 feet in width. On the north side, near the centre, stands the Experi- 
 mental Tank, having its base on a level with the bottom of a flume. 
 
 The flume, which is 5 feet wide and 3 feet 6 inches deep, runs 
 from the tank and terminates in an adjustable weir. The water flow- 
 ing through the flume may pass over or under the weir and may run 
 to waste or may be made to pass into five large carefully calibrated 
 tanks, 8 inches below the floor level and ranged in series on the south 
 side of the Laboratory. The covering of the tanks is on the level and, 
 indeed, forms part of the floor. 
 
 Over the easternmost of the tanks stands the Experimental Pump 
 on a base formed of suitably designed carrying girders or trunks. 
 
 On the west side, at convenient points along the flume, Ate. the 
 following pieces of apparatus • — A 16 inch Pelton Wheel, with brake 
 attachments, a Turbine Tester of special design and aii Experimental 
 Centrifugal Pump. Along the west wall is fitted up a Rife Hydraulic 
 Ram with all the necessary pipes and tanks for experimental work. 
 The pumps are driven from a line of 3^ inch steel shafcing near and 
 running parallel with the east side of the Laboratory. The shafting 
 is operated by a 100 H. P. Mackintosh & Seymour high-speed horizon- 
 tal engine, standing in an adjoining room. By means of an electro- 
 magnetic coupling, designed by Prof. Carus- Wilson, and connected 
 with a switch conveniently placed near the Experimental Pump, the 
 
 s -■ 
 
 f ■ 
 
 1: 
 
maiu fliaft can be almost instantaneously thrown in and out of gear 
 and without (sudden impact or shock, as the circular armature permits 
 a partial rotation until the resistauce is overcome. A 90 H. P. auto- 
 matic recording transmission Dj/namometer is placed on the shaft 
 between the magnetic coupling and the nctirest point at whicli power 
 is transmitted. An 8 inch line of piping makes a complete circuit of 
 the Laboratory near the ceiling. The several pumps and motors arc 
 connected with this circuit, and the movement of the water is con- 
 trolled by suitably placed 8 inch straightway valves, branch tees, 
 elbows, etc. By means of a short ver tical length of 8 inch pipin?, ter- 
 minating in a goose-neck, the pumps can be made to discharge into t'^e 
 top of the experimenti-1 tank from which the water passes into the 
 flume, then into the largo tanks, and is thus again available for supply- 
 The whole of the water u!L;i?d in the Laboratory is drawn from the city 
 high level reservoir, which gives at the base of the tank a pressure of 
 more than 120 lbs. per square inch. The city service is ccinected 
 with the 8 inch circuit, which cat viherefore, if desired, be made to act 
 as a supply pipe to the turbines and other motors. Provision ia also 
 made for connecting the latter directly with the city service. The 
 pumps and motors all discharge into the flume and the water then 
 pafsos over the weir where the volume of discharge can be measured- 
 If the volume is not too great it can be at once measured by passing 
 the wiitcr into the large calibrnted tanks. 
 
 The weir may be used the whole width of the flume without side 
 eontractions, but l:y means of suitable cheeks one or more side con- 
 tractions can be introduced and the width of the weir diminished to 
 any required extent, or the weir may be subdivided into two or more 
 independent wtirs. A large number of experiments have already been 
 uiado to determine the co-cfficicnt of discharge with and without side 
 contractions and with different depths of water over the weir lip. The 
 results will be given as soon as the experiments have been completed. 
 The water maybe conveyed to any one of the five tanks through an 
 iron channel provided with properly placed miinholes, and the five 
 tanks can all be connected together by means of a 10 inch pipe run- 
 ning along the bottom of a deep trough nest the wall, and having the 
 Mccessary valves and 6 inch branches communicating with the several 
 tanks. The water may also be run to waste through this 10 inch pipe. 
 In this channel and next the weir there is a flap-door with edges 
 inclined at 45° to the vertical. The edges of the gap closed by the 
 door arc also inclined at 45« to the vertical, and the fit bstwecn the 
 
 >^ 
 
 
 Mfli 
 
--.*K-.\.\-t-'^ ~.ti -^U:^^-mtJi^:»*<^- 
 
 .-SS«.iiSiR\*3«JS?-V*<r.1W»«W>S*-i£-*=-^i4?*'*>i^^ 
 
 •f^.r.' ^^x^^u 
 
i' s ^agg ^p it E a- 
 
 S'^ 
 
 * 
 
 . <.fi 
 
.*4. 
 
^^- 
 
 ■><'■%. 
 
 -.„ -r # 
 
 
 
 "f^ifV 
 
door and gap has been made as perfect as practicable. An india 
 rubber cord is inserted in an endless groove running along the centre 
 line of the edges, so that when the door is closed and pressed home it is 
 absolutely water-tight. The door can be instantaneously opened and 
 closed by means of a lever and a system of links acting as a toggle- 
 joint, and each movement is recorded by an electrical chronograph. In 
 any given experiment the door is opened and the water allowed to run 
 to waste until the head over the weir lip is steady, when at a signal 
 the door is instantaneously closed, when the water is conveyed by 
 the chnnnel into any or all of the tanks. 
 
 Tlio stand-pipe for the fire-hose rises vertically at the back of the 
 tank and extends to the full height of the building. At ^h:; base it is 
 provided with a number of unions varying in size from 6 to 1 inch, and 
 to these unions .are attached the lines of piping for pipe-flow ezperi- 
 ments. The position of the stand-pipe was selected so as to allow of 
 straight lengths of more than 400 feet of pipe being used. 
 
 To secure a unifo.'m pressure a Locke Regulator has been pro- 
 vided which responds, though slowly, to a variation in the pressure. 
 
 A special piece of apparatus for hose testing has been placed in 
 the south-west corner of the Laboratory. It is connected by hydraulic 
 piping with the Blake pressure pumps in the Testing Laboratory, A 
 large number of tests liave been made on the strength and on the 
 longitudinal and circumferential extensibility of different varieties of 
 hose, which in the great majority of cases was in lengths of 50 feet. 
 The pressure, which often exceeded 800 lbs. per square inch, was 
 directly indicated b; a standard Crosby Gauge, while the time and 
 pressure were also registered automatically by a recording gauge speci- 
 ally designed for this i¥ork. 
 
 Of the remaining apparatus the following may be briefly noticed : 
 
 A glass tank, 72 inches by 18 inches by 12 inches, with circular 
 diiipliragm chamber at one end. This serves to illustrate vortex ring 
 motion and uiso, with the aid of glass tubes with flared ends and of 
 different diameters, the critical velocity and other stream-line pheno- 
 nicna. 
 
 Inverted glass domes, with an orifice in the bottom, with which 
 are demonstrated the phenomena of circulo.' and spiral vertex motion, of 
 the invcrtion of the vein, etc. 
 
 A series of very carefully made nozzles with a perfectly smooth 
 bore, and having pressure gauge attachments at each end. Each nozzle 
 is 36 inches in length bstwecn the gauge connections, and has a taper 
 
 8 
 
corresponding to a diameter, varying from 3 inches to 2f inches in the 
 latgCBt to 3 inches to I inch in the smallest. 
 
 A scries of sixty hydrostutic jrauges, each witli a range of 20 lbs. 
 and embraoin'j; pressures up to 140 lbs. per square inch. The gauges 
 are graduated to tenths of a pound, and the range of every gauge is 
 overlapped by the two consecutive gauges. 
 
 A mercury column, 27 feet in height, is fixed to the north wall 
 near the experimental tank, and in addition to this there are several 
 small portable mercury columns, which are used in the experiments 
 for determining the resistance to flow in small pipes due to elbows, 
 bends, convolutions, etc. These pipes arc 13 in number, have a 
 smooth bore and are f inch in diameter. 
 
 The Laboratory is also supplied with a Veuturi and other piston 
 and rotary meters, a number of book .gauges, Darcy's improved Pitot 
 tube, brass standard gallon, quart and litre measures with glass 
 strikes, etc., etc. 
 
 Measuring Tanks.— Thcro are several copper measures of capa- 
 cities varying from 10 to 100 gallonw. They have been carefully cali- 
 brated, and the calibrations are frcf)Uontly checked. When in use 
 they are placed upon a plane-table with adjui-table iect so that a true 
 level can be always maintained. 
 
 Each of the largo tanks already referred to is fi feet by 3 feet 6 
 inches by 9 feet deep, and discharges into the 10 inch header 
 through a 6 inch straightway valve. Each tank is also connected with 
 a separate vertical 4 inch brass pipe, in which the water freely rises and 
 falls with tho water in the tank. This forms the float chamber. These 
 tanks have been carefully calibrated, and tho contents can be readily 
 measured to within the sixteenth of a gallon . The float is attached to 
 a vertical .'V inch brass rod with a pointer at the upper end, indicat. 
 ing on a brass plate the quantity of water in a tank. A fine cord, 
 fastened to the top of the' rod, rises vertically, passes around a friction- 
 less pulley, and carries a constant weight at tho end which counter- 
 balances the rod, etc., keeps the cord taut, and so prevents the pointer 
 from rubbing against the plat*;. 
 
 Experimental Tank.— The tank is of cast iron, \s 28 feet in 
 height, Fciuarc in Hcction, and has a sectional area of 25 nuare feet. 
 Every'care was taken to make the inside surfaces of the tank walls 
 perfectly flush, and to this end tho flanges, by which tho several sec- 
 tions were bolted together, were placed on the outside. At first tho 
 water discharged irom the tank was replaced by water admitted 
 
'«f?f" 
 
 
 into the top of the tank throuf-h a hose termiauting in a rose submergeJ 
 just below the surFace. Although the utmost care had been taken in 
 the design of this rose to reduce the eddy motion at efflux to a min- 
 mum, there was always an appreciable disturbance. The hose was 
 therefore extended until the rose rested on the bottom of the tank, 8 
 eet below the orifice ; with this arrangement a scries of orifice-flow ex- 
 periments were made, (the time in each case being the mean of that 
 given by two stop-watches) and the values of the coefficient of dis- 
 charge are given in the following tables : 
 
 
 Trukgdlar 
 
 BIFICG 
 
 or .05 
 
 SQ. IN. 
 
 AREA AND RKHAININO 
 
 Orifices 
 
 
 
 OF .0625 SQ. INS. AREi 
 
 . 
 
 
 
 
 
 K(|U<latcral tri- 
 
 
 
 Uectangle with 
 
 Rectangle with 
 
 Head 
 
 
 aii|{le with liuri- 
 
 Square with 
 
 vertical aides 
 
 vertical sldei 
 
 
 Circular. 
 
 zniital baee 
 
 vertical side*. 
 
 equal 
 
 to four 
 
 equal to lizteen 
 
 feet. 
 
 
 u|i|ierinoit. 
 
 T 8 
 
 
 
 times the width 
 
 times the width. 
 
 
 r 
 
 S 
 
 T 
 
 s 
 
 T 
 
 s 
 
 T 
 
 S 
 
 1 
 
 678 
 
 620 
 
 657 
 
 6:)l 
 
 ca:) 
 
 627 
 
 662 
 
 640 
 
 688 
 
 671 
 
 '?. 
 
 618 
 
 6i;{ 
 
 646 
 
 62S 
 
 6;{1 
 
 621 
 
 64."5 
 
 629 
 
 665 
 
 657 
 
 i 
 
 610 
 
 605 
 
 628 
 
 616 
 
 620 
 
 615 
 
 6:^1 
 
 620 
 
 642 
 
 643 
 
 6 
 
 007 
 
 601 
 
 628 
 
 6i:{ 
 
 615 
 
 612 
 
 627 
 
 616 
 
 634 
 
 636 
 
 8 
 
 606 
 
 601 
 
 621 . 610 
 
 613 
 
 609 
 
 624 
 
 613 
 
 631 
 
 632 
 
 in 
 
 604 
 
 600 
 
 618 
 
 (i08 
 
 612 
 
 608 
 
 621 
 
 613 
 
 629 
 
 629 
 
 n 
 
 60;{ 
 
 698 
 
 617 
 
 607 
 
 611 
 
 607 
 
 621 
 
 611 
 
 626 
 
 627 
 
 14 
 
 602 
 
 598 
 
 617 
 
 607 
 
 610 
 
 606 
 
 620 
 
 610 
 
 623 625 
 
 16 1 
 
 602 
 
 598 
 
 616 
 
 606 
 
 609 
 
 606 
 
 619 
 
 609 
 
 622 
 
 626 
 
 1R 
 
 601 
 
 597 
 
 615 
 
 605 
 
 607 
 
 605 
 
 618 
 
 608 
 
 622 
 
 623 
 
 20. 
 
 1 
 
 601 
 
 597 
 
 615 
 
 605 
 
 607 
 
 604 
 
 618 
 
 608 
 
 621 
 
 622 
 
 
 
 
 OrIKICKS OF .197 SQ. IN. IN 
 
 AREA. 
 
 
 
 
 
 
 Kquiintor- 
 
 
 
 Square 
 
 Kecta..gle III « 
 
 ■5' 
 
 .- 5J J, _ . 
 
 B'O.2 S.a 
 
 •a . 
 .s S • I' 
 
 Head 
 
 in 
 feet. 
 
 Clrci 
 
 liar. 
 
 itl tnaiiKli- 
 with hori- 
 
 ZOIltll 
 
 aid? up- 
 
 Square 
 ■.yith vsrt- 
 icnl siili'S. 
 
 with dia- 
 vertical. 
 
 wlthver- '~°^ „■ 
 tleal8ldes^.:2g5 
 
 pqual to gS-aSi 
 fi)Ui tlinesigV a " * 
 
 
 " .S o •• . 
 
 'liiif 
 
 
 
 
 [lermoBi. 
 
 
 
 
 the width. 
 
 
 |s"l 
 
 
 T 
 
 S 
 
 T S 
 
 T 
 
 s 
 
 S 
 
 T S 
 
 s 
 
 8 
 
 8 
 
 1. 
 
 624 
 
 618 
 
 627 627 
 
 623 
 
 628 
 
 623 
 
 635 640 
 
 641 
 
 658 
 
 659 
 
 2. 
 
 616 
 
 611 
 
 620 621 
 
 013 
 
 621 
 
 619 
 
 626 633 
 
 632 
 
 646 
 
 646 
 
 4. 
 
 610 
 
 607 
 
 015 615 
 
 000 
 
 617 
 
 614 
 
 019 629 
 
 629 
 
 637 
 
 637 
 
 6. 
 
 607 
 
 60.-) 
 
 613 613 
 
 004 
 
 614 
 
 012 
 
 010 625 
 
 627 
 
 634 
 
 633 
 
 8, 
 
 606 
 
 604 
 
 012 612 
 
 003 
 
 612 
 
 012 
 
 614 625 
 
 625 
 
 631 
 
 631 
 
 10 
 
 606 
 
 604 
 
 Oil 611 
 
 002 
 
 610 
 
 Oil 
 
 612 624 
 
 623 
 
 630 
 
 629 
 
 12. 
 
 605 
 
 603 
 
 611 611 
 
 001 
 
 010 
 
 Oil 
 
 611 622 
 
 622 
 
 027 
 
 626 
 
 14. 
 
 604 
 
 603 
 
 610 610 
 
 000 
 
 610 
 
 609 
 
 611 622 
 
 621 
 
 624 
 
 625 
 
 16. 
 
 606 
 
 602 
 
 610 610 
 
 600 
 
 610 
 
 609 
 
 610 620 
 
 621 
 
 624 
 
 624 
 
 18. 
 
 605 
 
 602 
 
 610 610 
 
 600 
 
 610 
 
 609 
 
 609 620 
 
 620 
 
 623 
 
 623 
 
 20. 
 
 604 
 
 601 
 
 609 609 
 
 600 
 
 ,--,-.3&.-^ 
 
 610 
 
 .-TTT'-.-x::: 
 
 609 
 
 602 620 
 
 620 
 
 622 
 
 622 
 
 N.R.— Inthe above Tables T indioates a tbtokness of plate of .It -In., and S iudioatet 
 that the orifice ia shari^edged, 
 
 6 
 
 li 
 
■'**«"=S*«!l»N(« 
 
 '^si^sr^r^s^T- 
 
 Tlie presence of the hose in the tank was not satisfactory, as it neces- 
 sarily interfered with the stream-line motion, and therefore affected to 
 a greater or less extent the values of the coefficient of discharge. The 
 hose was discarded, and the water is now admitted into a 3 inch 
 ohamber extending right across the bottom of the tank and containing 
 perforations on the lower surface through which the water flows to the 
 bottom and is there deflected upwards. Twelve inches above the 
 bottom the water is made to pass through a bafflo-plale perforated with 
 I in. holes, and 6 inches higher there is a second baflileplate also per- 
 forated with § in, holes. In order to equalize as much as possible the 
 flow from all points, the pitch of the holes in the upper plate was deter- 
 mined by the projections on a horizontal plane of equal distances on a 
 sphere of 10 ft. diar. with its centre at the centre of the orifice of dis- 
 charge. 
 
 There are two outlet pipes for fast and slow discharge, and there are 
 two inflow pipes, the one 3 ins. and the other IJ ins. in diameter. 
 Each of these pipes is controlled by a stop-valve. 
 
 With this new arrangement, the time being taken by an electric 
 chronogpap'^i, the following values for the co-efficient of discharge have 
 been deduced for sharp-edged orifices : — 
 
 Head 
 
 Circular. 
 
 .6199 
 .6131 
 .6081 
 ,6073 
 .6056 
 .6050 
 .6040 
 .6038 
 ,6032 
 .6031 
 .;,029 
 
 Square 
 
 Uectangular 
 Katio of sides 4:1. 
 
 Itectangular 
 Ratio of sides 16 : j. 
 
 Trian- 
 gular. 
 
 in 
 feet. 
 
 Sides ver- 
 tical 
 
 [diagonals 
 vertical. 
 
 .0276 
 .6277 
 .6177 
 ,6156 
 ,6138 
 ,6132 
 .6123 
 .6118 
 .6113 
 .6110 
 ,6108 
 
 Long side 
 vertical. 
 
 .6419 
 .6335 
 .6281 
 .6255 
 .6234 
 .6224 
 .6217 
 .6207 
 .6203 
 .6200 
 .6198 
 
 Long side 
 borizontaj 
 
 .6430 
 .6355 
 .6293 
 .6266 
 .0252 
 .6240 
 .6230 
 .6222 
 .6215 
 .6212 
 .6210 
 
 Long side 
 vertical. 
 
 Long side 
 horizontal 
 
 1 
 
 2. 
 
 4. 
 
 C 
 
 S. 
 10. 
 12. 
 14. 
 1«. 
 IH. 
 
 20. 
 
 .6267 
 .6204 
 .6162 
 .6137 
 .6127 
 .6116 
 .6109 
 .6104 
 .6099 
 .6096 
 .6094 
 
 .0633 
 .6503 
 .6409 
 .6.368 
 .6342 
 ,6323 
 .6311 
 .6304 
 .6301 
 .6299 
 .6291 
 
 .0644 
 .6510 
 .6415 
 .6372 
 .6346 
 .6,327 
 .6314 
 .6304 
 .6298 
 .6293 
 .6286 
 
 1 
 
 .6.359 
 .6280 
 .6228 
 .6202 
 ,6189 
 .6183 
 ,6177 
 .6176 
 .6171 
 ,6163 
 .6160 
 
 The manner in which the head of water in the tank is defined is 
 both simple and effective. A glass tube of 1^ in. diar. is fixed to the 
 tank by brackets and extends from the top to the bottom. On one 
 side of the gauge there is a brass scale graduated from a zero point in 
 the same horizontal plane as the centre of the orifice of discharge. A 
 carrier with a horizontal wire passing in front of the gauge slides up and 
 
 t> 
 
 m 
 
1 
 
 down, and any required head is obtained by bringing the necessary 
 scale graduation, the surface of the water in the gauge, the wire and 
 its reflection in a mirror at the back of the gauge, into the same hori- 
 zontal plane. There is a second indicator on the opposite side of the 
 tank consisting of a float uttachcd to an ordinary water-proof silk fish- 
 ing line passing over a large light frictionless pulley and then verti- 
 cally downwards in front of the tank. The cord is kept taut by a 
 weight at the bottom, and carries a friction-tight pointer which can be 
 easily and rapidly adjusted to indicate any required mark on a brass 
 plate fixed in a convenient position on the tank face, so that the opera- 
 tor working the valves has it constantly under observation. As soon as 
 the head of water in the tank has been determined by means of the 
 glass gauge, the pointer is moved into position opposite the mark, 
 and is kept there throughout the experiment. This obviates the neces- 
 sity of constantly watching the level of the water in the gauge which, on 
 account of tlie height of the tank, is often very inconvenient and 
 troublesome. Occasionally, however, it is advisable to check the 
 position of the pointer by observing the water-level in the gauge, as the 
 cord-indioator is extremely sensitive, and the cord itself necessarily 
 varies slightly in length, so tiiat small errors might otherwise be intro- 
 duced. 
 
 The head of water is brought to any required level by means of a 
 three-way valvo through which the water can either be admitted or 
 may be allowed to escape. The valve is provided with a long vertical 
 spindle, upon which handles arc arranged at different points in such 
 manner that one can be easily reached and operated from any position 
 in the height of the tank. Close to the cord indicator and within the 
 reach of the 0|)erator there is a ^-inoh pipe with valve, which is use- 
 ful for a fine adjustment when the inflow is only slightly in excess of 
 the discharge. 
 
 The values of the co-efficient of discharge (c^) were calculated 
 from the usual formula. 
 
 At'J2gh 
 
 The area (A) of each orifice was practically the same and equi- 
 valent to the area of a circle of ^-inoh diameter, or .19635 sq. inches. 
 
 The value of ^ (> 32.176) used in every case was that obtained for 
 Montreal by Commandant Deforges in 1893. 
 
 1 
 
:,*■ .• " ^ ii-CTy^a* »<n ai^ 
 
 I 
 
 At least two sets of mensurements were made for each head, and 
 the mean was adopted as comet if the results did not differ by more 
 than 3 in 10,000. 
 
 The possible errors in the several factors of the above formula 
 have been computed to be as follows : 
 
 For 20-ft. bead. 
 Error in Q 20 in 100,000 
 
 «« A 10 " 
 
 « t 6 « 
 
 " R 2 *♦ 
 
 .. h 1 " 
 
 For 1-ft. head. 
 20 in 100,000 
 10 " 
 
 1 *' 
 
 2 " 
 20 " 
 
 li 
 
 
 
 AMr Ai»# af /••* 
 
 Is- 
 
 
 , -f A^ Sl ^ ^ ^li^ ^^^^:^- 
 
 f» 
 
 K>.« »y /■«»'»»••''••• 
 
and 
 lore 
 
 lula 
 
 i 
 
 1--1- 
 
 .J 
 
 Perhaps the most important feature of the tank is the valve ar- 
 rangement. The valve is a gun-metal disc J-in. in thickness and 24-in8. 
 in diameter, fitted into a recess of the same dimensions in a cast iron 
 cover plate, with gun metal bearing facts, forming a water-tight joint 
 for the face of the disc. This cover pla » or body is bolted to an open- 
 ing in the front of the tank, and the inner faces of the cover plate or 
 disc are flush with the inner surface of the tank. 
 
 In the disc and on opposite sides of the centre there are two 
 screwed openings, the one 3 ins. and the other T-ins. in diameter. By 
 rotating tL^ disc each opening can be made concentric with a screwed 
 Ti-in. opening iu the body of the valve. The disc is rotated by means 
 of a spindle through its centre, passing through a gland in the front of 
 tlic valve body and operated by a lever on the outside. Gunmetal 
 bushes, with the required orifices, are screwed into the disc openings, 
 and when screwed home have their inner surfaces flush with the valve 
 surface, and therefore with the inside surface of the tank. By means 
 of n simple device, these bushes can be readily removed and replaced by 
 others without the loss of more than a pint of water. A cap with a 
 central gland is screwed into the TJ-in. opening of tlie valve body and 
 forms a practically water-tight cover. The valve is rotated so as to 
 bring the busli opposite the opening, and it is then unscrewed by means 
 of a special key projecting through the cap gland. The valve is now 
 turned bock until the opening is closed whon the cap is unscrewed, tbo 
 bush taken out and another put in its place. The cap is again screwed 
 into position, the valve rotated until the openings in the disc and tank- 
 side arc concentric, when the bush is screwed home by the key. 
 
 The utmost c are has been taken to form the orifices with the great- 
 est possible accuracy. The orifices arc worked in the discs approxi- 
 mately to the sizes required, and are then stamped out with hardened 
 steel punches, the sizes of which ha?e been determined with great ex- 
 actness by means of Brown ftSharpe micrometers. The diameters of 
 the orifices are also checked by a Rogers' comparator and a standard 
 scale. In some cases a discrepancy has been found between the sizes of 
 the die and its orifice, but the size obtained for the orifice is the one 
 which has been invariably used in the calculations. 
 
 A gun metal bush or shell, screwed into each of the two openings 
 in the main disc, carries a scries of orifice plates. The larger bush 
 takes plates with openings up to 4-ins. in diameter, and the smaller 
 bush takes plates with openings up to IJ-in. in diameter. The plates 
 are provided with a shouldered edge which fits against the correspond- 
 
 9 
 
r ja» t aiJ S M CTiB'P»a>q yB 1 »*i T 'WJ.'t4*'MH'^' ''^^ 
 
 t»4) l * i j- 
 
 «)0!<HI iH .w ji ttjU 'ff mtjiU ' H j yiiMat j V uljwwM i 
 
 ing rim of the bush and are screwed with the orifice iu any required 
 position by means of an annular screwed ring fitting the interior sur- 
 face of the bushing. The orifice plates arc gun metal discs, 4J-ins. in 
 diameter by J-in. thick for the large bnah and 2-in8. in diameter by 
 ^-in. thick for the small bush. 
 
 Each of the larger orifices, from 4-ins. to O-ins. diameter, is made 
 in a separate bush which fits the 7-in. opening, and any of which can 
 be easily taken out and replaced. 
 
 In "co-efficient of discharge" experiments, the water, on leaving 
 the orifice, passes either to waste or to the measuring tank, through a 
 bifurcated galvanized iron tubing, supported in a pivoted frame. The 
 water is first run to waste through one of the branches until a steady 
 head has been obtained, and the frame is then rapidly swung through 
 a small angle by means of a lever, when tlic water passes through the 
 other branch to the tank. As soon as the tank is sufficiently full, the 
 frame is swung back and the water agaio runs to waste. In the for- 
 ward and return movements, the lever makes and breaks an electric con- 
 tact, the interval of time occupied by an experiment being registered 
 by a chronograph. 
 
 In " co-efficient of velocity " experiments, the position of the jet 
 from an orifice is defined by vertical measurements from a straight-edge, 
 supported horizontally above the jet by a bracket on the tank face at 
 one end and at the other on a bearing, which admits of a vertical adjust- 
 ment. 
 
 I 
 
 MomaoMTAL mTHA..:MTrBer 
 
 -Oi —■■nil*- 
 
 10 
 
,.? 
 
 r -^ 
 
'J"ho steel straight-edge is 5^ft. in length, 2J-ins, in depth, g-in. 
 in width and is graduated so as to give the Iiorizontal distances 
 from the inner face of the orifice plate. The vertical ordinates are 
 meusured by a Vernier caliper specially adapted for the puipose. 
 The flat face of the movable limb is made to rest upon the upper 
 surface of the straight-edge, and the caliper arm hangs vertically. 
 A bent piece of wire, with a needle-point, is clamped to the other limb, 
 and by means of the screw adjustment, can be readily moved until it 
 just, touches the upper or lower surface of the jet. 
 
 The sectional dimensions of the Jet are determined by the jet 
 measurer. 
 
 One end of a horizontal 2-in. bar is attached to the front of the 
 tank and the other ?.s supported on a frame bolted to the sides of the 
 flume. A split cross-head, or sleeve, elides along this bar and may be 
 clamped by a tightening screw in any desired position. Upon tho 
 cross-head there is another split boss, or sleeve, through which a se- 
 cond bar passes at right angles to the first, and carries a similar cross- 
 head to that on the 2-in. bar, so that provision is made for a rough ad- 
 justment in a vertical plane. Through the latter cross-head passes a 
 smaller bar, and along this bar slides a third adjustable cross-head, or 
 caliper-holder, by which the caliper can bo swung round and receive its 
 final adju.'itment. For the measurements a 12-inoh Brown & Sharpe 
 Vernier caliper is used. A capstan head rod is clamped to each leg and 
 can be swivelled through any angle. Steel needle pointers are inserted 
 in the heads, and are clamped in such position as may bo required. la 
 making a measurement the steel points are first made to touch and the 
 corresponding readings taken. The points are then separated by slid- 
 ing the caliper heads apart, and the whole appat^.us is moved into posi- 
 tion. The points are finally adjusted so as to touch the surfaces of the 
 jet at opposite points, and readings are again taken. From the two sets 
 of readings the transverse dimension of the jet can be at once deter* 
 mined. 
 
 With this apparatus, jet measurements can be made to the one- 
 thousandth of an inch, and at any point between 72 inches and ^-in. 
 from the inner edge of the orifice plate, but rigidity is most essential. 
 
 Impact Apparatus. — This apparatus was constructed for the pur- 
 pose of determining the force with which jets from orifices,, nozzles, etc., 
 impinge upon veins of different forms and sizes. (See Fig. 1, r,. 1.) 
 
 A massive oast-iron bracket, 8-ft in length, has one end securely 
 bolted to the front of the tank, and tho other supported by a vertical tie- 
 
 11 
 
 P^ 
 
rod from one of the oak beams in the ceiling. The upper surface is pro- 
 vided with accurately planed slides, which are set level about 5-ft. 
 above the orifice axis. If, from any cause, the end of the bracket 
 farthest from the tank is found to bo too high or too low, the error can 
 bo corrected by loosening or tightening the nut on the tie-rod. 
 
 The balance proper is carried by a sliding frame which can be 
 moved iiorizontally into any position along the bracket by means of a 
 rack and pinion actuated by a sprocket wheel with chain. At one 
 end the frame has two equal arms with a common horizontal axis paral- 
 lel to the bra( set, and each arm has a stop on its lower surface which 
 serves to limit the oscillation of the balance. 
 
 The balance, in its mean position, consists of a main trunk with 
 horizontal axis rigidly conneuted with u vertical slotted arm and with 
 two equ:il horizontal arms at one end. Tiie common axis of the latter 
 is horizontal and perpendicular to the axie of the main tiuuk. The 
 hardened steel knife edges of the balance are4-ft. centre to centre and 
 rest in hardened steel Vees inserted in the ends of the sliding frame on 
 Ciich side of the bracket. The bottom of each Vee is in the same hori- 
 fontal lino (called the axis of the Vees) at right angles to the bracket. 
 
 A bar with the upper portion graduated in inches and tenths has a 
 slot in the lower portion, which is bent into a circular segment of 9^-ins. 
 radius. The bar slides along the slot in the vertical arm of the bal- 
 ance. A radial block, with the holder into which the several vanes 
 arc screwed, moves along the slot in the circular segment, and may be 
 clamped in any required position, the angular deviations from the ver- 
 tical being shown by graduations on the segment. 'J he centre of this 
 segment in every case coincides w'.th the central point of impact on a 
 vane, is in the vertical axis of the balance arm and is also vertically 
 below the axis of the Vees. Thus the jet can always be made to strike 
 the vane both centrally and normally. 
 
 The scale pan hangs frowi a knife-edge at one end of the horizon!aI 
 arjn.s uf the balance, while to the other end is attached a fine pointer, 
 which indicates the angular movement of the balance on a graduated 
 arc fixed to the sliding frame. The balance is in its mid-position when 
 the pointer is opposite the zero mark. 
 
 When a vane has been secured in any given position, the preliminary 
 adjustment of the balance is effected by movmg a heavy cast iron difo 
 aloog a horizontal screw fixed into the main trunk, x lie sensitiveness 
 of the balance is also increased or diminished by raising or lowering 
 heavy weights ou two vortical screws in the top of the tru*-''. 
 
 12 
 
11 
 
 Assume that the adjustments have all been made and that the jet 
 now impinges normally upon a vane. 
 
 Let W be the weight required in 
 the soiile pan to bring the balance 
 back into its mid-position. 
 
 Let f„ be the actual Ibrce of im- 
 pact determined by the balance. 
 
 Let Fi be the theoretical force 
 of irapnct deduced by the ordinary 
 formulae. 
 
 Then the ratio 
 
 Ft 
 
 miiy 
 
 be 
 
 
 called the co-efficient of impact. 
 
 Let y be the vertical distance of 
 the central point of impact below 
 
 the horifontal axis of the orifice, which is 36 ins. below the axis of the 
 Vees. The distance between this axis and the point of suspension of the 
 ecalc-pan is 24 ins. 
 
 Let <^ be the angle thiough which the water is turned on the 
 vane. 
 
 Let 6 be the angle which the tangent to the path of the jet at the 
 point of impact makes witli the horizontal. 
 
 Let // be the head over an orifico of sectional area A. 
 
 Then, 
 
 amJ I 
 
 F, cos ^ = 2 wc, clAh (1 - co8<^) 
 = 2 10 Crf c„il /t (1 -cos^) 
 
 = 4 w Ca c„ A h sin? -^ 
 
 ic being the specific weight of the water and c^, c„ and Cj the oo ef- 
 ficients of contraction, velocity and discharge, respectively. 
 Thus c, the co-efficient of impact 
 /;__ 6 JV 
 
 ^' vc^c,Ah »iV^(3 6+y) 
 
 For a flat vane and taking w r, 02^ lbs. per cub. feet, 
 
 .n2 fV 
 
 '^ 'c„c,.Ah(^6+y) 
 
 13 
 
A very few co-efficient of velocity (c) experime': «■ gave the fol- 
 lowing resulta : 
 
 Head in feet. 
 
 Co-efficient of /elooity (c„.) 
 
 4 
 
 .9950 
 
 8 
 
 .9960 
 
 12 
 
 .9957 
 
 16 
 
 .9960 
 
 20 
 
 . .9954 
 
 The mean of the values of r,, namely .9956, is the value used in 
 calculating by means of the above formula, j values of the co efficient 
 of impact given in the accompanying table: 
 
 I. Vanes with smooth polished surfaces. 
 
 Co-efficient of iaipict (c,) 
 Form of Vane Surface area Head over diar. of orifice being 
 
 orifice in ft. .5-in. .6769 in. 1.0002 in. 
 
 Surface area 
 
 in sq. ft. 
 
 .0491 
 
 « 
 
 « <i 
 
 « II 
 
 M II 
 
 Circular segment 
 
 on 35^ .0575 
 
 II i> 
 
 (( CI 
 
 M «• 
 
 (( II 
 
 Circular segment 
 
 oflSQo .0654 
 
 II i< 
 
 •( « 
 
 II II 
 
 M II 
 
 Circular segment 
 
 of 1660 0780 
 
 II 11 
 
 II II 
 
 M II 
 
 II II 
 
 4 
 
 8 
 12 
 16 
 20 
 
 4 
 
 8 
 12 
 16 
 20 
 
 4 
 
 8 
 12 
 16 
 20 
 
 4 
 
 8 
 12 
 16 
 20 
 
 .9691 
 .9684 
 .9725 
 .9749 
 .9767 
 
 .9048 
 .9189 
 .9319 
 .9360 
 .9377 
 
 .8789 
 .8969 
 .9004 
 .90.36 
 .9068 
 
 .8668 
 .8877 
 .8955 
 .8982 
 .8861 
 
 .9777 
 
 .9723 
 
 .9677 .9777 
 
 .9520 .9561 
 
 U 
 
 .9360 .9i)60 
 
 iMWMaM 
 
 flMtM 
 
he fol- 
 
 sed in 
 
 fficient 
 
 ct (c.) 
 
 g 
 )02 in. 
 
 1723 
 
 
 
 
 Co efficient of inpact (c 
 
 Form of Vane Surface area 
 
 Head over diar. of orifioo b^ing 
 
 
 in gq. ft. 
 
 orifice in ft. .5-in. .6769 in 
 
 1.0U02in 
 
 Circular segmcut 
 
 
 
 
 
 of 180O 
 
 .0982 
 
 4 
 
 .8297 
 
 
 «' 
 
 II 
 
 8 
 
 .8454 
 
 
 II 
 
 II 
 
 12 
 
 .8544 
 
 
 C( 
 
 II 
 
 16 
 
 .8572 
 
 
 M 
 
 <i 
 
 20 
 
 .8623 .9219 
 
 .9635 
 
 11. 
 
 Vanes with surfaces 
 
 rough as cast. 
 
 
 I^lat 
 
 .0491 
 
 4 
 
 1.0168 
 
 
 « 
 
 it 
 
 8 
 
 1.0276 
 
 
 li 
 
 It 
 
 12 
 
 1.0343 
 
 
 <i 
 
 II 
 
 16 
 
 1.0411 
 
 
 « 
 
 ti 
 
 20 
 
 1.038 1.0295 
 
 1.0179 
 
 Circular segment 
 
 
 
 
 
 of 180° 
 
 .0982 
 
 4 
 
 .7447 
 
 • 
 
 <( 
 
 II 
 
 8 
 
 .7527 
 
 
 « 
 
 II 
 
 12 
 
 .7570 
 
 
 II 
 
 (1 
 
 16 
 
 .7593 
 
 
 II 
 
 II 
 
 20 
 
 .7567 .8467 
 
 .9203 
 
 777 
 
 561 
 
 
 '£^U 
 
 •t^ l«S* ■••■ 
 
 r>60 
 
 16 
 
 i 
 
■e^ iSrY"-' »'*-') 
 
 lA^fli <teil- 
 
 K— ) 
 
 Id the above diagrams, fig. 1 represents the variation of the c, for 
 diffei-ODt angles of deflectioa. 
 
 The results obtained for each head or velocity are combined into 
 a curve. 
 
 The angle of deflection denotes the total angle through which the 
 direction of motion of tiie water is turned, i.e., 90° for a flat vane ; 
 180° for a hemispherical vane. 
 
 Fig. 2 shows the variation of the coefficient c, with the head or 
 velocity of the impinging stream. The curve indicates the value for 
 aach angle of deflection. The general indication of the curves i^ that 
 the co-efficient increases '"ith the velocity. 
 
 The Testing of Motors, Gauges and Pressure Chamber. la motor 
 testing it is of importance to know the pressure of the water at 
 certain points in the supply (or delivery) pipe, and, generally speak- 
 ing, it 18 in.praoticable to employ cither a mercury or a water gauge. 
 The pressure is therefore observed by standard Bourdon gauges, of 
 small individual range, which aro frequently osted, a record being made 
 of the errorn. The method usually adopted to diminish the oscillating 
 effect in the gauge due to fluctuation in the flow is to connect the bore 
 of the pipe with an annular cliamber by a number of small holes. In 
 the McGlill Laboratory these lioles have been replaced by a continuous 
 opening around the bore, less than .005 inch in width, with the obvious 
 result of obtaining a better mean pressure. Similar chambers are also 
 being used in experiments on the resistance of bends to flow. There 
 are four s^ets of bends of 1 in., 1^ in., 2 in, and 3 in, diar., and each 
 set coDBista of 30 bends, 10 having a radius of one diameter, 10 oi tioo 
 
 16 
 
 ' '-tiMVMPBlMMnMMMl^ 
 

 
D^M■■^aM8iiN0NWBW^'^^'<s)^''* 
 
 
mssm 
 
 il 
 
 n.o 
 
 i 
 
 diameters and 10 of four diameters. At the central cross-section of each 
 bend, provision is also made for ascertainini? the pressure, either by 
 a mercury column or by a gauge, at the extremities of the radii to tlie 
 outer and inner surfaces of the bore. The chambers for the bonds are 
 combined with union couplings, of the same bore, which allow the 
 attached part to be swivelled through any required angle. 
 
 Speed Indicators.— The speed of the motor is taken by a revolution 
 counter and also by a tachometer. A slidins? slotted sleeve at one end of 
 main shaft of the motor can be made to engage with the spindle of the 
 revolution counter, which can therefore be readily thrown in and out of 
 gear at the commencement and end of a test, and the readings can be 
 taken at leisure. The tachometer is supported on a bracket fixed to the 
 motor frame, and is driven by a cord pussiag over a pulley on the motor 
 
 shaft. 
 
 JSraAje.— Besides a Halpin brake of 50 H.P. capacity, the laboratory is 
 equipped with a friction brake which has been designed by Mr. Withy- 
 combe, the guperintendent, and which can be used with wheels both of 
 the horizontal and the vertical type. It possesses many novel features 
 of which the most important are : - 
 
 First, that ft is .self-adjusting and 
 
 Second., that a single direct weighing gives the total drag. 
 
 The brake wheel is of cast-iron and turned inside and out. Tlie outer 
 and inner surfaces of the rim are hhroudod, the shrouding on one si.lo 
 being formed by the solid disc connecti' g the rim with the boss. A 
 stream of water is delivered tangcntially into the channel inside the 
 wheel througli a narrow rectangular mouthpiece of nearly the same 
 width as the channel. The surplus water is carried away by a scoop 
 of somewhat similar form but reverse in action. The tight portion of 
 
 17 
 
 i\ 
 
tlu brake band is of leather, and the slack portion consists of two strips 
 of copper. In the mean position, each portion embraces about one- 
 h.-ilf of the circumference of the pulley, and its end is attached to a lug 
 projecting from a rod. The lug to which the slack portion is joined in 
 capable of sliding along the rod and, by means of a screw, can be 
 adjusted so as to increase tlie slack tension as desired and therefore to 
 produce any required tolal drag. The rod in the direction of its 
 lenirth has a practically frictionless range of 5 inches, whicli corres- 
 ponds to a variation of about 16" in the angle of band contact. The 
 resultant force along the rod is the diflFercncc between the tight and 
 slack tensions, and measures the drag. The force is balanced by dead 
 weights which are placed in a tray at the top of the rod for a vertical 
 wheel and, if the wheel is horizontal, in a scale-pan suspended by a 
 cord which passes over a frictionless pulley and is attached to the head 
 on tiic rod. 
 
 If, from some cause, tlie band friction should increase, the drag 
 would also increase, and there would be a corresponding movement of 
 the rod. Thus, a portion of the leather band would be unwrapped, 
 while an equal portion of the copper band would be brought into contact. 
 But the frictional coefficient for leather exceeds that for copper, so that 
 the drag would be less and would continne to diminish until it again 
 balanced the weight. The reverse, of course, would be true, if the 
 band-friction should diminish. The rod would move in the opposite 
 direction, an excess of the leather band would be brought into contact 
 and the drag would continually increase until equilibrium was again 
 restored. 
 
 Hence, within a certain range, the band will find a position of 
 equilibrium, although the friction may vary, and the total drag will 
 then be measured by the dead weight in the tray or in the scale-pan. 
 
 If th-' movement of the rod should l)e so great that it may come 
 against one of the stops provided to limit its action, the drag can be re- 
 adjusted by means of the screw attachment. This, however, is very 
 unlikely to happen, as the range already allowed is sufficient to 
 admit of a large variation in the value of the co-efficient ot friction. 
 It has been found that the best results are obtained by running the 
 wheel without any lubricant on the rim ; care should be taken to pro- 
 tect the rim from water or oil, which would necessarily produce a con- 
 siderabie variation in (he frictional resistance. 
 
 This brake has been in use only a few months, but in the several 
 trials which have been made it has fully realized the expectations that 
 
 13 
 
 t « iii i'M ii m«iii ,i'",; iTriaf i 'BM M i i W j»aer-. 
 
 ii 
 
1 
 
 dras 
 
'^i 
 

 i 
 
 1} 
 
 1- 
 
 Jiad been formed of its efficiency. It has been employed in measuring 
 directly off the jack shaft the power developed by a 6 in. turbine with 
 vertical axis and a 16 in. Pelton wheel with horizontal axis. 
 
 It may bo noted that the weight of the rod and connected parts 
 has been made exactly 10 lbs., which, of course, forms part of the 
 dead weight in the case of a vertical wheel. 
 
 Measizrement of Water.— The whole of the water is discharged 
 into the flume, and passes over the weir into the large calibrated tanks. 
 If the quantity is too great to be measured in tha tanks, the water is 
 run to waste and the discharge calculated from the normal weir formula. 
 Co-efficients of discharge have been found for various depths over the 
 lip, and the coefficient for any particular d^pth can be very approxi- 
 mately determinod by interpolation. The depth over the lip is obtained 
 by means of the " depthing " app-aratus, which consists of a deep girder 
 stretching across the flume and carrying three hock gauges with Verniers 
 which read to .001 inch. 
 
 Centrifugal Pump. — The Centrifugal Pump is erected over the 
 flume in a framework which allows it to be raised or lowered so that the 
 heights of suction and discharge may be varied at will. For this pur- 
 pose the piping is made in interchangeable lengths of 2 feet. The 
 pump is driven by a 9 inch belt and discharges into the ceiling circuit 
 already described. From this circuit the water is delivered into the 
 top of the Experimental Tank, flows into the adjoining flume, passes 
 over an intercepting weir for calibration and is then again conveyed 
 along the flume to the pump. Thus, the same water can be used over 
 and over again. 
 
 Turbine Tester.— The turbine is supported upon an annular flange 
 bolted to the bottom of a cast-iron cylinder. An 8-inch te'j is secured 
 to the crown of the cylinder, and a cover with a specially designed gland 
 is bolted to the upper flange of the tee. The jack -shaft passes through 
 this gland, which forms an almost frictionless bearing. No packing is 
 required, aa provision hat. been made for carrying away any slight 
 leakage that might occur. The jack-shaft passes through a piece of 
 pipe screwed to the bottom of the cover and extending downwards to 
 the cylinder, so that it is prv/tected from the impulsive effect of the in- 
 flowi.^g water. The supply pipe is connected with the horizontal 
 branch of the tee, and the entrance of the water is controlled by an 
 8 inch straight- way valve placed at some distance from the opening. 
 
 The gates of the turbine, for example, one of the New American 
 inward and downward flow type, are worked by means of a shaft ex- 
 
 19 
 
 > 
 
 \ji 
 
 -Z^lTf^TdiU 
 
 WiWi^e^j^^^t*''''*^ ijniL^lf& ^ 
 
 
CCI 1 i)(uU 
 
 tending from a pinion geareil to the toothed quadrant and passing 
 through a gland in the crown of the cylinder. The upper end of the 
 shaft is provided with a handle and pointer, which indicates on a 
 graduated quadrant the extent of the gate opening. 
 
 Suitable pressure gauge connections have been arranged in the 
 opper and lower parts of the cylinder. 
 
 The power of the turbine is u ^termined by thu friction-brake 
 
 already described. 
 
 Experhnental Pump.-f:\m puuip is of the vertical triple throw 
 single acting plunger type, and is driven by two 10 inch double leather 
 belts running on 48 inch pulleys formed on the outer cranks, or discs. 
 The plungers are 7 ins. in diameter and have an 18 inch stroke. Tht- 
 approximate maximum delivery is estimated to be 1,000 gallons per 
 minute when the pump is running at a speed of 150 revolutions per 
 minute against a pressure of 120 lbs. per s,v inch. The suction valve 
 chambers are placed directly over the calibrating tank nearest the east 
 wall, and draw the water from this tank through two 10-inoh suction 
 pipes. Bach discharge valve chamber is directly connected with a 
 12 inch header, which discharges into the 8 inch ceiling circuit. The 
 water may be made to flow in almost a direct line to the point of 
 discharge, or it may be made to pass around the three sides of a rec- 
 tangle 80 that the effect of the additional bends and increased length 
 of piping may be estimated. The water flows into the experimental 
 tank at a point 20 feet above the level of the discharge valves. 
 
 One of the features of the pump is the provision made that the 
 valves can be taken out and replaced by others of a different type. 
 The valves at present in sttft are a liiedler valve and two others with 
 groups of 36 circular disc valves of 1 j inches diameter in each. 
 
 In addition to the usual pressure gauges, tachometer and revolu- 
 tion counter, the pump is fitted with a specially designed continuous 
 triple indicator apparatus, which autographically records during any 
 given uateofa trial the speed, variation and duration of the valve 
 cLar^her pressure at any point of the stroke. Sight holes are pro- 
 vided for observing the movement of the valves and indicators for 
 recording their lift. A special recording gauge also registers the 
 pressure in the delivery pipe. 
 
 As the pump is for experimental work, it has been made unusually 
 heavy, its totol weight being about 55,000 lbs. The plungers, valves 
 and valve scats, all internal screws, nut», etc., are of bronze, and weigh 
 
 more than 3,700 lbs. 
 
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