Correspondence on Hydro-Electric Installations.

Abstract

thought that the Paper, descriptive of works of great importance, was all too short, and many would lament the lack of detail, especially as regarded troubles experienced. He wished to ask why the construction of the Talarn dam was not carried on continuously. The figures for overall efficiency given on p. 300 presumably referred t o the Canlarasa installation, and were stated to be " confirmed by individual plant and machine trials,'' though it was not always clear to which power-house the Author referred. If the trials were actually carried out on the site, it would be valuable to know exactly how the quantity of water discharged from the turbines was measured. The percolation mentioned on p. 304 was remarkable ; it would be of interest to know what the temperature of the percolation water was, and at the same time the temperature of water at the bottom of the reservoir. The turbines at Camarasa were shown fitted with relief valves. What was the size of the valves, and the time of opening and closing on one set, when full load was thrown off ; and had the guaranteed over-pressure of 18 Ibs. been complied with ? It would