JOHN MURPHY, general manager of the United Traction Company, of Pittsburg, reports the average life of motor gears on his line as two years, and the average life of pinions, nine months. He is employing the gears and pinions of the Simonds Manufacturing Company. The service is an exceedingly severe one, on account of the many grades on the line. The average life of trolley wheels is 1,000 miles, and the conditions under which they operate are quite severe, as the company has on its main line eighteen railroad crossings. A tempered copper wheel is employed. ACCORDING TO a recent correspondent of The Buffalo Express, in the Pennsylvania oil region during the last year over 300 gas engines have been placed on oil leases and are doing satisfactory work. The engines vary from 10 to 50 horse power. Every big machine shop in the oil regions is turning out gas engines. The machine shops are also using gas engines to drive their own machinery. During the last year twenty of the Standard Oil Company's pipe line pumping stations have been equipped with gas engines. In all the new stations and in old ones where new machinery is needed, the gas engine will be preferred. Where natural gas cannot be had and coal was formerly burned, gasoline is used. The pumping station engines are all provided with electric ignition. IN A recent issue of The Railway Age is published the following, based upon the last report of the Interstate Commerce Commission: "Last year the railways of the United States carried over 13,000,000,000 passengers one mile. They also carried 95,000,000,000 tons of freight one mile. The total amount paid in dividends on stock was $87,603,371--call it $88,000,000. Of the total earnings of the railways, about 70 per cent. came from freight service and 30 per cent. from passenger service. Let us assume, then, that of the $88,000,000 paid in dividends, 70 per cent., or $61,600,000, was profit on freight service and $26,400,000 was profit on passenger service. Let us drop fractions and call it $62,000,000 from freight and $26,000,000 from passengers. By dividing the passenger profit into the number of passengers carried (13,000,000,000), we find that the railways had to carry a passenger 500 miles in order to earn $1 of profit--or five miles to earn 1 cent. Their average profit, therefore, was less than two-tenths of 1 cent for carrying a passenger (and his baggage) one mile. By dividing the freight profit into the freight mileage (95,000,000,000) we find that the railways had to carry one ton of freight 1,530 miles in order to earn $1, or over fifteen miles to earn 1 cent. The average profit, therefore, was less than one-fifteenth of a cent for carrying a ton of freight (besides loading and unloading it) one mile."