Popular Science Monf/ili/
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��The Very High Cost of Writing Letters
HAVE you ever figured out the cost per letter of your business correspon- dence? Taking into considera- tion the cost of stationery and stamps, the salafy of the stenographer, cost of all ac- cessories to the typewriter, all overhead charges, and last, but not least, cost of time of the man who dictates the let- ters, it works out at forty cents per letter, and that is an absolute minimum!
���Why this formidable -looking array of pipes? Just in order to separate natural gas from oil
��That Elusive Keyhole Simply Must Be Found
THERE are times in the life of most jolly good fellows when they find it quite difficult to find the exact geo- graphical location of that narrowly cir- cumscribed opening into which their latch key is supposed to fit.' But even persons not included in the class of good sports often have difficulty to find the keyhole, particularly at night or in cases where the door is located in a dark hall or corridor. The key hole guide invented and patented by Ernest E. Brown of Waukegan, 111., is designed to give relief in all cases where the finding of the key- hole is, for any rea- son, connected with difficulties. These guides, which form a kind of trough with sides slanting toward the keyhole, are ham- mered into place over the regular doorplate, and conduct the key unerringly to the key- hole with absolutely no effort at all.
��Pror\g5 bent bacK 'over door locK
����5ides slar\t mT^ toward Keyhole
��Showing construction and application of the handy keyhole trough herein described
��Oil and Gas Mix, and So They Are Separated Out West
MANY oil wells yield both oil and gas so, with such a plant as is shown, the flow is forced directly from the well into a large main pipe. The gas separates from the oil and rises to the top of the pipe, passing over through the small inverted U-shaped pipes and into the smaller main.
For many years natural gas in oil wells was considered a nuisance and was allowed to waste, but now, on account of its fine heating, fuel and power qualities, large investments are made to conserve and utilize it. The day of the picturesque burning gas well, lighting the country at night for miles around as an ad- vertisement of a na- tural gas region, is practically a thing of the past. Such a spec- tacle is rarely seen now and when it does oc- cur it is looked upon as an example of poor engineering.
Natural gas is, nowa- days, a valuable com- mercial commodity, and a number of cities use it exclusively in lieu of coal gas for heating, lighting, and power purposes. It is, of course, much cheaper than coal gas.
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