Section III., 1884. [ 81 ] Tkans. Eoy. Soc. Canada. 



IV. — A Particular Case of Hydraulic-Ram or Water-Hammer. 

 By C. Baillairgé, C. E. 



CRead May 24, 1884.) 



When I wrote last to Mr. Bouriuot announcing, for the next meeting of the Society, 

 the reading of a paper by Mr. Steckel, " On the Form of the Contracted Liquid Vein as 

 affecting the present Theory of the Science of Hydraulics," I had no idea of contrib- 

 uting a paper of my own. Since that date an accident has occurred to the main conduit 

 of the Quebec "Water "Works, which may prove interesting and instructive, from a scientific 

 point of view, to the world at large and to the hydraulic engineer in particular. 



The Quebec aqueduct is, as compared with other gravity-works, almost unique in 

 some of its leading features. The fountain head at Lorette, through which the supply of 

 water from Lake St. Charles is derfved, is not less than 486 feet above the pipe which 

 passes under the bed of the river St. Charles near the city. Some ten years ago there 

 occurred in this portion of the conduit a leak, originating in an air-hole in the spigot 

 end of one of the pipes within the feucet, and so small as to be invisible at the time when 

 the pipe was laid, now thirty years ago. This hole, by the constant passage through it of 

 a jet of water undtn- a pressure of 208 lbs. to the square inch, gradually enlarged to a 

 diameter of about one inch and a half; when, seriously affecting, as it did, the supply in 

 the city, it was decided to stop the leakage by applying, over it and around the pipe, a 

 wroiight-irou baud an inch thick and four inches and a half in breadth. 



Twelve months afterwards the leak broke out again, and, upon examination, it was 

 found that, in this short interval of one year, the water had, under the great pressure 

 alluded to, forced the leaden joint, and, in the edge of the ring next the faucet, eaten away 

 a space of an inch in depth by two in breadth. One of the ribbon pieces of the wooden 

 box, which encloses the conduit beneath the bed of the river, and which was some six 

 inches in section, was nearly eaten through by the impinging jet, and the four and a half 

 inch sheet-jiiling, which formed the side of the enclosure, was worn away to the extent of 

 three inches. 



I mention these facts as worthy of attention, and to elicit the opinion of scientists and 

 practical men upon the questions, how far the water itself, if pure, could have produced 

 the effects related ? or whether it is not possible and even probable, that there issued 

 forth from the aperture in the pipe some of the sedimentary matter found in it and perio- 

 dically scoured out of it by openiug the smaller pipe (8") leading into the river from the 

 eighteen-inch conduit? This sediment, however, is deposited in the tube and' rests on 

 the bottom of it, while the leak was in the upper half of the conduit, and, as the velocity 

 of flow through the pipe is but some two and a half to three feet per second, it becomes 

 a question whether and, if so, to what extent, the reaction of the jet could stir up the 



Sec. III., 1884. 11. 



