PARK AND CEMETERY. 
83 
IWfACADAM roads disintegrate by 
various processes. Traffic destroys 
the surface, pulverizing and loosening 
it so that it blows away in the form of 
dust. When the top coat of screenings 
is thus destroyed, the road has lost its 
roof, and water, instead of being shed 
quickly to the gutters, penetrates into 
the lower layers of larger stone and does 
endless damage. 
Under heavy loads ordinary macadam undergoes 
a certain amount of internal movement which is 
very destructive. The stones below the surface, 
grinding against each other under great pres- 
sure, exert a mutually abrasive effect, resulting 
in a general disintegration and breaking-down. 
The modern way to protect roads against such 
wear is to bond them with Tarvia. 
Tarvia is a dense, viscid compound of coal tar. 
It fills the voids between the stones and forms a 
tough, plastic matrix. On the Tarvia surface 
thus formed automobile wheels do not cfamage, 
since the tenacity of the Tarvia is great enough 
to resist the traffic. 
Used in the interior of the road, Tarvia keeps 
the stone in its proper position and prevents in- 
ternal shifting, rubbing and grinding. These 
two results of the use of Tarvia bring about 
great economies in maintenance. 
A tarviated road lasts so much longer and needs 
so little care that the cost of Tarvia is more 
than compensated for. 
“Booklets on request. 
BARRETT MANUFACTURING COMPANY 
New York Chicago Philadelphia Boston St. Louis Cleveland Cincinnati Pittsburgh 
Detroit Birmingham Kansas City Minneapolis Salt Lake City Seattle 
The Paterson Mfg. Co., Limited: Montreal Toronto Winnipeg Vancouver St. John, N.B. Halifax, N. S 
Sydney, N. 
Phelps Grove, Springfield , Mo. 
Roads that 
do not wear out — 
