POWER FROM THE TIDES SIR,—How is it that the tides,
as a source of power, have been neglected for so long? In places like the Bristol Channel, where the rise and fall are considerable, millions of horse-power could be generated. Remember also that droughts do not affect the tides as they do many other hydro- electric schemes. Two large enclosures are necessary, but the one that retains the water at high tide need only be shallow, and it need not be adjacent to the other enclosure, as water can be •led between the two by a canal. On a rocky coast-line there are many suitable sites for the chamber which empties itself at low water and into which the turbines would discharge. Under present conditions in 4ngland I can think of no more promising expenditure than that of a small amount on the survey of possible sites and an estimation of the expenditure that would be involved to generate a given amount of horse power.—Yours, &c.,