626 



Popular Science Monthly 



A Simply Constructed Vapor Plug 

 for Automobile Engines 



VAPOR plugs are fast becoming a com- 

 ponent part of the automobile engme. 

 One can be made that will serve the purpose 

 and the cost will be only for the price of a 

 small pet cock and a piece of tubing. 

 I Two methods may be used in making 



Small pet cock interposed in the manifold 

 of an engine instead of a regular vapor plug 



the connections for the air inlet at the pet 

 cock. The first one shown is where the 

 pet cock is turned into a tapped hole in the 

 manifold body and the rod connects a 



handle on the dashboard. The second 

 method calls for a piece of tubing to form 

 a connecting piece from the manifold 

 body to the pet cock where it is placed on 

 the dashboard within easy reach of the 

 driver. In the manufactured plug the 

 operation is automatic; but the simply 

 constructed device must be worked by 

 hand. It is claimed that these plugs will 

 reduce the carbon formation, give more 

 mileage per gallon of fuel, more power and 

 speed. When starting the engine or on a 

 cold day close the cock. It works best 

 when the engine is hot. — R. F. Becker. 



A Substitute Drafting-Rule Made 

 from Ordinary Flat Rule 



FIRST buy a common flat rule with a 

 metal strip embedded in a slot running 

 lengthwise of the rule. Next get a piece of 

 cardboard the length and width of the rule. 

 Glue this firmly to the underside of the rule. 

 The cardboard raises the edge of the metal 

 strip a trifle off the drawing paper, thereby 

 allowing the ink from the drafting-pen to 

 flow freely and without danger of smear- 

 ing. Rulers like the one described are 

 not expensive and when treated according 

 to instructions will give as much satisfac- 

 tion as a steel scale. 



Succeeding in Radio Work 



Advice to the Radio Amateur 



THE future development of radio teleg- 

 raphy is largely in the hands of the 

 earnest non-professional experimen- 

 ters of to-day. From the ranks of this 

 country's 300,000 amateurs are to be 

 recruited many of the men who will make 

 wireless telegraphy of greater and greater 

 public value in the years to come. 



Amateurs have been handicapped by a 

 lack of authoritative technical guidance. 

 Much of the instruction given them has 

 been and is entirely inaccurate. 



The Popular Science Monthly, in 

 accordance with its policy of expressing 

 scientific facts truthfully and clearly, has 

 arranged for a series of wireless articles of 

 a new sort. In them some of the hardest 

 problems of the radio amateur will be 

 explained and solved by Mr. John L. 

 Hogan, Jr., who has agreed to aid the 



Popular Science Monthly's readers in 

 this way. Mr. Hogan is Chairman of the 

 Standardization Committee and Vice-Presi- 

 dent of the Institute of Radio Engineers, 

 Honorary Member of the Radio Club of 

 America, member of the American Institute 

 of Electrical Engineers, and a Research 

 Engineer. His inventions and scientific 

 writings are widely known in the radio field 

 throughout the world, and his views are 

 authoritative. Best of all, however, he is 

 able to explain abstruse scientific and 

 engineering matters so simply and clearly 

 that they can be grasped even by beginners 

 in the study of wireless. 



Mr. Hogan believes in the radio ama- 

 teurs, and is going to help us help them. 

 Watch for the series of articles, which will 

 commence in an early issue of the Popular 

 Science Monthly. 



