26 Transactions of the State Agricultural Society. [July, 



sills, dry rot follows. The sills should not be larp;e; four inches 

 square is sufficient. They should be perfectly bedded into the 

 earth, and there should be broken earth under them, care being- 

 taken that they should not rest firmly upon rocks or other hard 

 substances, that will not allow them to settle. 



All earth formations of this nature will settle some, and the sills 

 must be permitted to go down as the rest of the structure settles, 

 or a space for air would be left between the plank and the earth, 

 and the sills would thus support the plank; whereas the plank 

 should rest upon the earth at every point. Nothing is gained by 

 wide or deep sills, and the whole support of the road is the earth 

 that is covered by the plank, and the amount is in no wise in- 

 creased by wide sills. The chief use of sills, is to grade by, and 

 to keep the road in form until the earth has become settled. 



There is in the vicinity of Toronto a short plank road that has 

 no sills at all under it, and the grade is very nearly as exact as in 

 those roads where sills are used. 



The plank having been laid, the next thing is to grade a road 

 some ten or twelve feet wide on one side, and two or three on the 

 other, by taking earth from the ditches on each side, and bringing 

 it by a dirt scraper just up to and even with the upper side of the 

 plank, so that if a wheel runs off the track it passes upon a smooth 

 surface of earth. The ends of the plank should not be laid even, 

 but a part should project from two to four inches by the general 

 line, to prevent a rut being cut just along the ends of a plank. If 

 the ends of the plank are even, and a small rut is made, the wheel 

 of a loaded wagon will scrape along the ends for some distance 

 before it will rise up to the top of the plank, unless the wagon 

 moves in a direction nearly across the road; but if the wheel 

 cannot move two feet forward without coming square against the 

 edge of a projecting plank, the difficulty of getting on the road is 

 avoided. It is not necessary to pin or spike the plank to the sills. 



Perfect drainage must be secured, and to that end the ditches 

 must be deep and wide, and good sluices wherever water crosses 

 the road. This is an important point — drain perfectly. 



The thickness of the plank must be decided by the amount of 

 travel. If it is sufficient to insure the wearing out, and not the 

 rotting out of the timber, four inches is the thickness; if that 

 thickness is not justified by the travel, then three inches should be 

 used, but not less. The kind of timber is, too, a point that must 

 be controlled by circumstances. Pine is used at Toronto. Hem- 

 lock on the Salina road. In some of the western states it is likely 

 that oak might be procured at a reasonable price. The number 

 of feet (board measure) of lumber required for two sills four inches 

 square, for one mile, is 14,080 feet. Plank, three inches thick, 

 for a single track eight feet wide, will measure 126,720 feet. The 



