Popular Science Monthly 



267 



Applying Hot Road Material 



TO be impervious to water and to re- 

 sist wear to the greatest possible 

 degree, roadways must be impregnated 

 with hot tar or some similar material. 

 This condition demands vehicles which 

 combine the necessary distributing ap- 

 paratus with a plant for heating the road 

 material. 



The truck illustrated herewith is of 

 five tons capacity and is one of three re- 

 cently installed in Baltimore, Md. The 

 truck has a four cylinder gasoline motor, 

 and this also operates a powerful air 

 compressor with which the hot liquid is 

 forced out on the roadway. 



With the Forty-Niners 



THE historically important discovery 

 of gold in California was made in 

 January, 1848, at John Sutter's mill on 

 South Fork of American River near Co- 

 loma. a point only ten or fifteen miles 

 southeast of the town of Auburn. From 

 1850 to 1853 the greatest yield was de- 

 rived from the gravels, and the largest 

 annual output for this period was more 

 than sixty-five million dollars in 1852. 

 There was some reaction in 1854, due to 

 previous wild speculation, but a produc- 

 tion of about fifty million dollars a year, 

 chiefly from placer mines, was main- 

 tained up to the year 1861. 



To obtain the best results, the tar to be used in making roads must be sprayed while hot. 



A great tank truck has been built, which has a small boiler on the rear of the chassis to 



keep the material at the desired temperature 



The material within the tank is main- 

 tained in a liquid state with the aid of 

 a small flash-steam boiler, which is 

 mounted at the back of the chassis and 

 which may be fired with either kerosene 

 or gasoline. From this generator, super- 

 heated steam is led through the material 

 in a continuous flow by means of pipe- 

 coils. 



THE most remarkable gold and silver 

 beetles are to be found in Central 

 America. Some have the appearance of 

 burnished gold while the others are 

 like silver. They are worth $35 apiece. 



At first the gold was won chiefly 

 from the gravels along the present 

 streams. Those who first got possession 

 of the rich bars on American. Yuba, 

 Feather, and Stanislaus rivers and some 

 of the smaller streams in the heart of the 

 gold region, made at times from one 

 thousand to five thousand dollars a day. 

 In 1848 five hundred to seven lumdrcd 

 and fifty dollars a day was not unusual 

 luck ; but, on the other hand, the income 

 of the great majority of miners was far 

 less than that of men who seriously de- 

 voted themselves to trade or even to 

 common labor. 



