Popular Science Monthly 



427 



A Revolving Barrel as a 

 Concrete Mixer 



AN oil barrel suspended b> 

 . chain from a 

 metal frame in such 

 way that the barrel 

 is revolved about 

 its own axis is 

 the principal 

 part of the 

 concrete mix- 

 er shown in 

 the accom- 

 panying illus- 

 tration. The 

 mixer is to be 

 used for the 

 small job where 

 a big mixer 

 would be unnec- 

 essary but where 

 hand-mixing 

 would be too 

 slow and expensive to be considered. 



The apparatus is operated by a one and 

 one-half horsepower gasoline motor mount- 

 ed on a portable carriage. It is especially 

 adapted for the use of farmers or small con- 

 tractors in the laying of concrete barn 

 floors, house steps, sidewalks and the like. 



The sand, cement and stone are shoveled 

 into the barrel in the proper amounts. 

 Then the barrel is revolved about its axis 

 by a belt, driven from the motor, 

 water being added to the mixture 

 during the process. The chain sup- 

 porting the barrel passes over two 

 trunnion blocks at the top of the 

 frame. These are con- 

 nected by a bell-crank 

 with a handle which 

 can be pulled down for 

 unloading. 



Sand, cement and stone are shoveled into the barrel in 

 proper amounts and mixed by revolving the barrel on 

 its axis, water being added during the process as needed 



TENSION CABLE' 



What Poor Pavements Cost the 

 Automobile Owner 



running an elec- 

 tric delivery wagon 

 over pavements 

 and measuring the 

 amount of power 

 required at dif- 

 ferent speeds 

 the condition 

 of the pave- 

 ment and its 

 resistance to 

 traction have 

 been o b - 

 tained. At 

 the rate of 

 twelve miles 

 an hour it 

 takes tw^enty 

 per cent more 

 power to run 

 a car on a poor 

 asphalt pavement than on a good one. On 

 a poor, soft macadam pavement it takes one 

 hundred and twenty-five per cent more 

 power. This taxes each owner about 

 twenty-five dollars annually for roads. 



Eliminating the Bumps from 

 the Motorcycle Ride 



ONE of the largest American motor- 

 cycle manufacturers has just brought 

 out a stock model equipped with a hori- 

 zontal opposed motor, which is 

 designed to reduce vibration 

 and thereby provide a smooth- 

 ly running motorcycle 

 at all speeds. The two- 

 cylinder, four-cycle mo- 

 tor has its cylinders 

 placed fore and aft. As 

 shown in the accom- 

 panying cross-section 

 fRONT view of the motor, 

 lOTDR ^jjg crankpin ends 

 of the connecting 

 rods are attached to 

 a one-piece balanced 

 crankshaft. By this 

 method of cylinder plac- 

 ing, the vibration set up 

 in one cylinder by the 

 reciprocation of its pis- 

 ton is offset by that in 

 the opposite cylinder, 

 and in this way the 

 jolting of the motor- 

 cycle is avoided. 



The new smoothly-running 

 motorcycle from which the 

 vibrations have been elimi- 

 nated, and the cross- sectional 

 view of the motor, showing 

 the placing of the cylinders 



