Popular Science Monthly 



O 



421 



desired slope or arch, according to the 

 adjustment of the coulters and scraper. 

 The frame of the machine is provided 

 F the same size as a pencil, this tire* with a universally movable wheeled axle at 

 gage fits in the automobilist's pocket, its forward end, to which the front wheels 



A Tire Pressure-Gage No Bigger 

 Than a Pencil 



It measures the tire pressures 

 in five-pound increments and 

 works on the plunger pump 

 principle with a small piston 

 forced out by the air pressure 

 against a coil spring. The 

 piston rod is graduated in 

 pounds and has notches on one 

 edge which keep the rod ex- 

 tended to the highest pressure 

 until it is snapped back by a 

 push of the finger. 



This is 45 lb. 

 pressure 



Three Roadmaking 

 Machines in One 



ANEW grader that does 

 the work of several ma- 

 chines heretofore required for 

 finishing up a road has been 

 invented by Charles M. Ander- 

 son, of Denver, Colorado. 



The principal element of the 

 invention is a vertical, ad- 

 justable frame having coulters 

 which loosen and distribute the 

 earth. Following the coulters 

 comes an adjustable scraper, 

 which levels the earth pul- 

 verized by the coulters. Following the 

 scraper is a roller which packs the ground 

 down, forming a level road surface of any 



are mounted. 



This construction of the frame 

 makes it possible to operate the ma- 

 chine in any desired direction and 

 over rough and broken surfaces with- 

 out danger of breaking or unduly 

 straining the working parts of the 

 machine. Either tractor or horse 

 power may be used to run the ma- 

 chine. 



Increasing England's Crops 

 by Electricity 



ONE way England will help 

 to prevent German sub- 

 marines from starving her out is 

 by increasing her home crop by 

 electricity; Experiments have 

 been under way for determining 

 how high frequency electric cur- 

 rents will best stimulate crop 

 PHteVeep growth. Prof. V. H. K. 

 Blackman, of South Kensing- 

 ton, the eminent agriculturist 

 who is in charge of the work, 

 has already shown on a small 

 scale how oat crops can be in- 

 creased from fifty to eighty- 

 five per cent. This work is to be extended 

 upon cereals and other field crops which 

 will be planted over no less than fifty acres. 



—Spring 



Metal 

 piston 



Circular 



rubber 



ipple 



tire valve 

 open 



The pencil -like gage 

 works on the plung- 

 er pump principle 



A road-grader which does the work of several machines. It loosens the earth, distributes it, 

 pulverizes it, and packs it, forming a level road surface of any desired slope or arch 



