100 HIGHWAY CONSTRUCTION 



The coal-tar filler is best applied by pouring the material from 

 buckets, and brooming it into the joints with wire brooms. Jn order to 

 fill the joints effectually, it must be used only when very hot. To 

 secure this condition, a heating tank on wheels is necessary. It should 

 have a capacity of at least five barrels, and be kept at a uniform tem- 

 perature all day. One man is necessary to feed the fire and draw the 

 material into the buckets; another, to carry the buckets from the heat- 

 ing-tank to a third, who pours the material over the street. The latter 

 sta -ts to pour in the center of the street, working backward toward the 

 curb, and pouring a strip about two feet in width. A fourth man, 

 with a wire broom, follows immediately after him, sweeping the sur- 

 plus material toward the pourer and in the direction of the curb. This 

 method leaves the entire surface of the pavement covered with a thin 

 coating of pitch, which should immediately be covered with a light 

 coating of sand ; the sand becomes imbedded in the pitch. Under the 

 action of traffic, this thin coating is quickly worn away, leaving the 

 surface of the bricks clean and smooth. 



Tools Employed in Construction of Block Pavements. The 

 principal tools required in constructing block pavements comprise 

 hammers and rammers of varying sizes and shapes, depending on the 

 material and size of the blocks to be laid ; also crowbars, sand screens, 

 and rattan and wire brooms. Cobblestones, square blocks, and brick 

 require different types of both hammers and rammers for adjusting 

 them to place and forcing tljem to their seat. A cobblestone rammer, 

 for example, is usually made of wood (generally locust) in the shape of 

 a long truncated cone, banded with iron at top and bottom, weighing 

 about 40 pounds, and having two handles, one at the top and another 

 on one side. A Belgian block rammer is slightly heavier, consisting 

 of an upper part of wood set in a steel base; while a rammer for granite 

 blocks is still heavier, comprising an iron base with cast-steel face, into 

 which is set a locust plug with hickory handles. For laying brick, a 

 wooden rammer shod with cast iron or steel and weighing about 27 

 pounds is used. A light rammer of about 20 pounds' weight, consist- 

 ing of a metallic base attached to a long, slim wooden handle, is used 

 for miscellaneous work, such as tamping in trenches, next to curbs, etc. 



Concrete=Mixing Machine. Where large quantities of concrete 

 are required, as in the foundations of improved pavements, concrete 

 can be prepared more expeditiously and economically by the use of 



