MR. RHODES ON POWER PLANTS

Mr. G. I. Rhodes, electrical engineer of the Interborough Rapid Transit Company of New York City, delivered an illustrated lecture yesterday afternoon on "The Economics of Power Plant Operation."

Mr. Rhodes pointed out that every plant has to be built to carry the maximum load, and that this maxamum load is very much greater than the average load. He showed the finctuations of night and day, and of winter and summer, both for lighting and railways; and compared the different kinds of engines used. In running a power plant it is the fixed charges that must be watched closely, and Mr. Rhodes figured that the average fixed charges per annum for the various different engines amounts to 12 1-2 per cent. of the initial cost, the distribution being as follows: interest, 6 per cent.; depreciation, 5 per cent.; and insurance and taxes, 1 1-2 per cent. Since the fixed charges are so important there has been a tendency of late to make the engines carry as large a load as possible, in other words to force them.