GOVERN ME'SITAL WORK FOR COUNTRY LIFE 407 



course of gravel or slag and a top of crushed stone. 

 Of the gravel roads in class B, 3,415 miles had been 

 built to June 30, 1920 ; while the roads in classes 

 C and D were manifestly less favored, since only 286 

 miles of class C and 11 miles of class D had been 

 constructed at the same date. On the other hand, 

 there had been constructed 783 miles of the class E 

 type, which is a macadam road with or without a 

 bituminous binder, and properly bonded. The con- 

 crete type belongs to classes B, C, D and E, while 

 classes F and are entitled to an additional $2,500 

 a mile and trunk lines may receive State reward to 

 50 per cent of their cost but not to exceed $15,000 

 a mile. 



The surface sands and gravels of Michigan yield 

 abundant material for the construction and main- 

 tenance of roads. The United States Geological Sur- 

 vey reports for 1919 a production of 2,639,483 short 

 tons of gravel, 539,800 of building sand, 204,045 

 of paving sand, and 67,916 of railway ballast, in 

 addition to large quantities of sand used for manu- 

 facturing and other purposes. There was undoubt- 

 edly much material produced and used locally that 

 did not appear in the record. In addition enormous 

 quantities of waste rock from the iron and copper 

 mines and from the quarries are available and are 

 similarly employed. ^luch use also is made of the 

 stamp-mill sand that is a by-product of stamp-mill 

 operations along Portage Lake and Lake Superior 

 in the copper region. 



