THE CIVIL ENGINEER AND ARCHITECTS JOURNAL. 



[.Ianu^rv, 



WHITELAW AND STIRRAT'S PATENT WATER MILL.' 





Fig. 1 is ;i side elevation of the new watei-miil, in which figure 

 some of the parts are drawn in section. Fig. 2 is a plan showing the 

 arms and other parts of the machine. The main pipe a a carries the 

 water which drives the machine into its arras, from a reservoir or any 

 suitable jilace on a higher level than the arms ; h h are the arms, 

 which are hollow ; the water passes into them at the centre part c, 

 and escapes out at the jet-pipes dd; c c is the main or driving shaft 

 of the machine, which is shown cast in one piece witli the arms ; /is 

 a bevel pinion, and g a bevel wheel ; by means of which wheel and 

 pinion the rotary motion of the machine is communicated to the hori- 

 zontal shaft /(, which again communicates the power of the machine 

 to any machinery which it may be intended to work; i ii is a large 

 bracket fixed to the wall or building kk; this bracket supports the 

 shaft e c, while the bracket / carries one end of the shaft //. The jier- 

 pendicular jdane which passes through the parts represented in section 

 in the elevation, Fig. 1, passes through the points m m in the plan, 

 Fig. 2. The top journal or bearing n of the main shaft has a number 

 of collars on it; for, if there were but one collar, it would require to 

 be made larger in diameter than the collars shown in Fig. 1, in order 

 to get a sufficient quantity of bearing surface ; but if the diameter of 

 a collar be increased, the friction will be greater, as then the rubbing 

 surface is more distant I'roin the centre of motion; so, if a sutficient 

 quantity of bearing surface is obtained by a number of collars, there 

 w ill be le9« friction than if only one is used to resist the pressure, 

 (y (/ are holes through which the water escapes from the basin under 

 tlie arms into the tailrate after it has left the machine. As the arms 

 iiave a rotary motion, and the pipe ii a is fixed to the building under 

 it, there must be means provided to prevent the escape of water at 

 the place where the main-pipe meets the arms. A contrivance suit- 

 iiljle for this purpose is shown in Fig. 1 ; it consists of a ring or pro- 

 jection round the underside of the aperture c, and of a part p turned 

 cylindrical at the place where it fits into the pipe a a. A leather, 



* We are indebted for this description to a pamphlet by James AVhitelaw, 

 and for the use of the wood engravings to the Editor of the Mechanics' 

 Jlagaiiiie. 



similar to what is used in ]>acking the large piston in a Bramah press, 

 is inserted into the recess w ic, turned inside of the top part of the pipe 

 a a, in order to prevent the escape of water betwixt the pipe and the 

 cyhndrical part oi p. It will now be clear that if the part ;;, and the 

 ring on the underside of c, are accurately turned and ground upon each 

 other at the place where they meet, the pressure of the water in the 

 main pipe will act upon tlie under edge of p, and press it in contact 

 with the projecting (jart round the aperture c, and in this way keep 

 the joining of those parts water-tight. There is a flanch outside oi p, 

 with holes bored in it, to receive steadying-pins fixed to the top part 

 of the pipe a u; these pins are seen in Fig. 1 ; they prevent the part 

 p from re\olving, and are fitted so as to allow p to rise or fall. There 

 is another use for the flanch roundly, which is this: — a little rope-yarn 

 is wrapped betwixt it and the main j)ipe, to prevent the part p from 

 sliding down whenever tlicre is not a sufficient pressure of water in 

 the main pipe to support it. The pipe a a is bored out to receive 

 the part ji, which is fitted so as that it will slide easily up or down in 

 the bored part; rrrr are the stay-bolts which support the arms; 

 i i are valves, and g i a t are levers which work upon the centres It, 

 and form a connexion of these centres with the valves. There is a 

 lever on the top, and one on the bottom side of each valve. The 

 rods u n form a connexion with the levers s / s /, and the springs vvrt, 

 fixed to the arms. The end next the valve of each jet-pipe (see 

 Fig. 2) is a circle drawn from / as a centre ; and each valve is curved 



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I, +Ia' 



to fit and work corrcotly upon the end of its pipe. The levers atii 

 are adjusted so that the valres ss will work without rubbing upon the 

 ends of the jet-pipes, in order to get quit of the friction as much as 

 possible ; Ijut it is not essential that the valves should be correctly 

 water-tight. It will be clear, that if the machine revolves so fast as 

 to make the united centrifugal forces of the valves s s, the rods u ji, 

 the levers s I s t, and the springs, greater than the weight that will 

 bend the springs r ti !T to the distance shown in Fig. 2, the valves 

 will recede from the centre of the machine till the force of the springs 

 gets sufficient to overcome the centrifugal force of the valves, &c. 

 Therefore, the centrifugal force will cause the valves to cover tlie 

 ends of the jet-pipes, and so allow less water to escape, and thus 

 diminish the force of the water on the machine whenever it goes 

 quicker than the proper speed, if the springs are considerably bent 



