POLTTECSNIC ASSOCIATION PROCEEDINGS. 6X7 



open the joints to the filtration of water, either up or down through 

 the pavement. Furthermore: the joints are very much increased 

 in number and extent over what they would be with large blocks, 

 making it much more difficult to render it impervious to water; 

 which seems to be a necessary condition for a good wooden pave- 

 ment. In the only construction of this kind, which has, so far, 

 been adopted to any extent, the grooves for the horses' feet are 

 only obtained in one direction, at right angles to the length of the 

 street; whereas, if necessary at all, they are as necessary at the 

 intersections of other streets as elsewhere, in proportion to the 

 length occupied by those lateral streets. The plan of constructing 

 and fastening together of the blocks in such plans, has also not 

 been of so firm and substantial a character as it is capable of being 

 made, especially with larger and heavier blocks; and it will not 

 be disputed, that this construction is not the best to get the greatest 

 durability of the materials. Yet, although this description of 

 pavement has apparent defects, it has, in the opinion of many, 

 based upon practical experience and tests, undoubted advantages 

 over almost every description of stone pavement. 



Such plans as require iron in their construction, either as a base, 

 or by bolts to hold the blocks or sections in position, are liable to 

 the objection of the rapid deterioration of the iron from the action 

 of the water and earths upon it; the loosening of the bolts from 

 contraction and expansion, and to other specific objections — in the 

 different plans so far introduced — which need not be mentioned 

 here. 



Knowing, as we do, the requirements which are necessary, and 

 that the defects of the constructions referred to, are so great as to 

 be serious objections, the plan now submitted was designed to 

 overcome those objections as far as practicable. 



NEW YORK WOODEN PAVEMENT — GENERAL DESCRIPTION. 



It will be seen by the specifications, that this pavement consists 

 of large and substantial blocks of wood, prepared against decay 

 and fire, preferably of rectangular shape, and from six to nine 

 inches in depth, varying according to the character of the travel 

 of the street, and having a large area of bearing surface, generally 

 not less than one square foot, superficial area, to rest upon. These 

 blocks are grooved in their faces at intervals of about three and 

 one-quarter inches, with deep transverse vertical grooves of about 

 three-fourths of an inch in width, and from three to five inches in 



