TRANSACTIONS OF THE SECTIONS. 12/ 



iron may be safely loaded far beyond what lias hithei'to been deemed 

 prudent, still it is extremely probable that the bars are advancing, by 

 however slow degrees, to ultimate destruction. 



On Paving Roads and Streets ivith blocks of Wood, placed in a verti- 

 cal position. By John Isaac Hawkins, Esq. 



The subject, the author observed, has latterly become one of consi- 

 derable interest. Although seven patents have been taken out in this 

 country within less than twelve months, there is no specimen of the pave- 

 ment calculated to afford the means of forming a sound public opinion 

 on the subject. He had attentively watched, from 1827 to 1831, the 

 eflPect of much travelling over wooden pavement, well executed, in the 

 principal thoroughfare of Vienna, and observed that it appeared to 

 wear away less than any other kind of paving material whatever. In 

 this opinion he was confirmed by inquiries which he made relative to 

 the condition of a piece of wooden pavement laid about three years in 

 the Broadway of New York ; and he had been informed that a stone 

 of near twenty tons' weight had been drawn on a carriage over it 

 without appearing to make the least impression. From these circum- 

 stances he considered that roads formed of sound wood, with the grain 

 vertical, might be made so even as to constitute a sort of universal 

 railway, on which carriages might be drawn by a small proportion of 

 horse-power, and on which steam carriages might run as safely and 

 almost as fast as on railways. The directions to be attended to in the 

 formation of efficient and durable roads on this principle, which the 

 author gave, were comprised under the following heads : — 1. The 

 wood must be chosen from the heart of sound trees. Larch and other 

 resinous firs offer excellent materials at moderate prices. 2. The 

 blocks, which are to be laid contiguously, must be cut to an exact 

 gauge, so as to fit closely and evenly together, and no block must be 

 higher than another. 3. The depth of the blocks should be at least 

 that of a breadth and a half, a firm lateral support being found neces- 

 sary to stability. Each block, when rectangular, is supported by four 

 others, and when formed into hexagonal prisms, which appears to be 

 preferred, each block is supported by the six surrounding ones. The 

 hexagonal prism being found to afford the greatest quantity of wood 

 from a tree when the diameter of the prism is as large as can be cut 

 out of the whole diameter of the tree, that figure is generally adopted, 

 and has been fairly tested by experience. 4. The blocks must be laid 

 on a bed firmly made with gravel, shingle, hard rubbish, or other 

 material, well rammed down, and made even, previously to laying the 

 blocks. 5. A thin layer of only half an inch of fine gravel must be 

 spread evenly over the levelled surface at the time of laying the blocks, 

 to favour their adjustment. 6. The blocks must be laid so as to pre- 

 sent an even upper surface before they are rammed, in order that the 

 ultimate making them level shall not depend so much on the effects of 

 the rammer as on the evenness of the bed. It is essential that the 

 blocks be cut from dry wood, and used soon after being cut, lest their 

 figure vary by warping. 



