MECHANICS AXD USEFUL ARTS. 61 



ERICSSON'S WATER METRE. 



TIIE following is the specification of a patent granted to Mr. Ericsson 

 for an improved water metre : " The principle which distinguishes my 

 invention from all other things before known, in an instrument having 

 two cylinders provided with pistons, connected with cranks at right 

 angles, or such other angles as will enable the pistons alternately to 

 act on the crank shaft to rotate it, consists in connecting the two pis- 

 tons with their cranks, so that while the shaft is impelled by one 

 piston the other shall remain at rest at the end of each stroke, until 

 the shifting of the valves is completed, for the purpose of insuring the 

 accurate measurement of the fluid passing through and acting as the 

 motive force. My invention in the above apparatus also consists in 

 determining the range of motion of the pistons, by means of stops at 

 each end connected with the cylinders and pistons, instead of doing 

 this by the cranks ; by reason of which I am enabled to measure the 

 fluid passing through with the utmost accuracy, a result which could 

 not be obtained if the motions of the pistons were determined by the 

 crank, for the least wear of either the crank-pin or the journals of the 

 shaft, or the boxes in which these work, or the slightest change in the 

 position of the cylinders relatively to the parts with which the pistons 

 are connected, occasioned by strain or wear, would of necessity vary the 

 amount of water discharged at each stroke. My invention in the 

 before-mentioned apparatus also consists in attaching to the instrument 

 an outer casing, through which the fluid to be measured passes, and 

 from which it enters the cylinders, which casing incloses the valve and 

 valve gear, as also the other moving parts, and the upper ends of the 

 cylinders, that the various moving parts may work in the fluid, to be 

 lubricated thereby, whilst at the same time the various joints are pro- 

 tected by being pressed with a nearly equal pressure on all sides by the 

 fluid ; and also avoiding the use of packing-boxes for the sliding parts 

 of the mechanism. What I claim as my invention, is, connecting the 

 two pistons with the two cranks of a crank-shaft, in manner substan- 

 tially as described, so that at the end of each stroke of either of the 

 pistons it shall remain at rest, while the crank-shaft is being impelled 

 by the other piston, so that the valves shall be shifted whilst the piston 

 is at rest. I also claim, in an instrument for the purpose herein speci- 

 fied, determining the range of motion of the pistons by means of stops 

 connected with the cylinders and the pistons, in combination with the 

 connection of the pistons with the crank, or cranks, by means of a joint 

 having sufficient play to permit the pistons alternately to remain at 

 rest while the crank-shaft continues to rotate. I also claim inclosing 

 all the moving parts of an instrument in the surrounding casing 

 through which the water, or other fluid, passes to be measured, con- 

 structed, and operating in the manner and for the purpose substan- 

 tially as described." 



IMPROVEMENT IN APPARATUS FOR BORING FOR WATER. 



MR. JOHX THOMSON, of Philadelphia, has invented an improvement 

 in machines for boring for water, for which he has taken measures to 



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