Popular Science Monf/ili/ 



(177 



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. 





