The Bridgeport evening farmer., 1911-08-11
FINE ROADS RUINED
 BY AUTOMOBILES
Efforts to Make Roads Automobile
 Proof
(Hartford Courant.l

(HartfOrd COurant.
 Like the old contests between bat tleships, armor and heavy projectiles has been the ten-year fight that has been going on between the rural road and the automobile. The first auto mobiles with their low. speeds did lit tie damage to the macadam surfaces, but when speed increased and motors became more powerful, the rear wheels of the cars with their heavily weighted rubber tires ground the brit tie macadam like an emery wheel. Engineers were dismayed to see their costly surfaces, built as they thought to endure many years of travel ruin ed in a single season. The crushed stone which they had transported at great expense to make a smooth, cleanly road surface was scraped away by the clinging tires and scat tered to the winds by the draft of the cars. The office of public roads in the department of agriculture, ex- perimenting on a Long Island high way with high powered automobiles, settled beyond all doubt that this was the source of the damage when 1t dis covered that the driving wheels of the automobiles revolved considerably more times per mile than front wheels of the same diameter, indicating a certain amount of slip" The effect of this "slip" on a dry, brittle mac adam road surface hardly needs to be demonstrated. In0 ldCk Ol l6IldClly in ordinary macadam under such strains was responsible for its inabil- ity to endure this type of traffic.
 It had once been thought that it was the vacuum caused by the pas sage of the cars which sucked the dust out of the roadway, but with this scientific demonstration to settle the question as to the real cause of the injury, road engineers everywhere turned to the problem of building more tena cious road surfaces. French engineers years before had discover ed the desirability of binding roads with tar compounds as dust proven tive and American engineers, follow ing the French experiments, develop ed what has now become widely known as the tarviating process. The tarvia which is used is a viscid bitu- men derived from coal tar.
 Automobile Topics" has the fol- lowing illuminating explanation of the different kinds of tarvias and the uses to which they are put
 It's function is to fill the voids in the macadam and enclose the stone in a tough plastic matrix The ac- ton is somewhat like that of cement in concrete. The tarvia concrete, however, is not rigid or brittle, but retains a certain elasticity and capa- plastic surface the driving wheels simply roll down the surface and make it smoother with use. They cannot tear loose the stone from the plastic matrix and they have little or no pulverizing effect.
 In appearance tarviated macadam resembles sheet asphalt, although of course it only costs a fraction as much. It is not designed to with stand the strain imposed on sheet asphalt streets, but it is satisfactory for the lighter traffic of suburban or6C mi oITfn Iai1 
 The tarvia processes-there are several of them-provide the answer to all the typical macadam road prob lems. The problem of maintaining an old and well-worn macadam road, for example, is solved by an applica- ton of Tarvia B, the lightest and of the tarvias, designed pri- marily for dust suppression. This ! Tarvia B process will save an old road | for a year, usually making water l sprinkling unnecessary and prevent l ing erosion by water or attrition by | automobile traffic.
 For more thorough applications, | there is the Tarvia process, usually | for roads where a smooth | for example, in parks, cemeteries, etc. | Tarvia A is denser than TarVia and | has more tenacity and bind l ing power. It is somewhat more ex- pensive because it is so dense when | cold that it cannot be poured and l requires the use of heating apparatus | to prepare it for application Lake | Tarvia B, it reduces maintenance ex- | penses, makes the roads automobile | proof, and completely prevents the | formation of dust.
 The third tarvia process is for new | roads, or old roads that are being re- or resurfaced. This gives opportunity to use Tarvia x, an ex- ceptionally dense and tough bitumen | of great durability and binding power.