WOOD-PAVING. 



569 



to its cheapness Scots pinewood is also used and has proved to 

 be as durable for this purpose as Pitch pine. 



Generally injected wood is used, zinc-chloride is said to 

 have given better results in this respect than creosote. The 

 wood is used either in rhombs, or rectangular prisms, placed 

 on a slightly arched layer of concrete, molten asphalt being 

 poured between the blocks, which are afterwards covered with 

 a layer of fine gravel and well rolled. 



The blocks of wood are 6 inches to 12 inches long, 3 inches 



it-paving. 



broad, and 6 inches to 7 inches thick ; when rectangular they 

 are placed endways, and when rhombic, as in the figure. 

 Experience in London and other large cities gives the 

 following results. 



[There are also some important points to be considered, 

 especially noise from traffic and wear-and-tear of tyres; in these 

 respects w r ood and asphalt are evidently superior to granite or 

 other hard stone. As regards the various kinds of wood, 

 softwood wears away evenly and does not impair the concrete 

 beneath it. Hardwood wears less rapidly, but unevenly, and 

 injures the concrete below, so that it must be taken up when 

 fresh wooden blocks are laid. Non-absorbent wood is the most 

 hygienic, as much horse-urine permeates absorbent wood. Tr.] 



Blocks of Scots (red) pine and other wood are used also for 

 the flooring of stables, threshing-floors, or outdoor staircases. 



