CASE WHERE THE ALLEN VALVE PROVED ITS VALUE.
On one of the leading railroads in this country, an engineer was running a locomotive on a fast train where it was a hard matter making the card-time. A few minutes could be saved by passing a water-station; but this was done at serious risk, for the tender would nearly always be empty by the time the next water-station was reached. The master mechanic of the road determined to equip this engine with the Allen valve: and, after the change was made, there was no risk in passing the water-station; for there always was a good margin of water in the tank when the next watering-place was reached. The engine seemed to steam better, because the work was done with less steam; and there was a decided saving of fuel. The change made the engine smarter, and there seems to be no limit to the speed it can make. This valve can be applied to any locomotive with trifling expense. When an engine is designed specially for the Allen valve, the steam ports and bridges are usually made a little wider than for the ordinary valve. The only real difficulty in adopting the valve is getting the casting properly made, so that the supplementary port will not be too rough for the passage of steam, and the thin shell will be strong enough to stand the pressure.