YORKSHIRE. --------+-------+---------------------------+-------- | | Dimensions. | | +-------+--------+----------+Ultimate Test No.|Weight.|Length.|Breadth.|Thickness.|Stress. --------+-------+-------+--------+----------+-------- K | lbs. |inches.| inches.| inches. | lb. 1918 | 184 | 36 | 24·07 | 2·46 | 4·744 1919 | 163 | 36 | 24·03 | 2·22 | 3·398 1920 | 107 | 36 | 23·90 | 1·50 | 1·459 +-------+-------+--------+----------+-------- Mean | 151 | 36 | 24·00 | 2·06 | 3·200 --------+-------+-------+--------+----------+-------- CAITHNESS. --------+-------+---------------------------+-------- | | Dimensions. | | +-------+--------+----------+Ultimate Test No.|Weight.|Length.|Breadth.|Thickness.|Stress. --------+-------+-------+--------+----------+-------- K | lb. |inches.| inches.| inches. | lb. 1921 | 215 | 36 | 24·06 | 2·59 | 17·274 1922 | 178 | 36 | 24·05 | 2·15 | 12·711 1923 | 114 | 36 | 23·90 | 1·38 | 6·211 +-------+-------+--------+----------+-------- Mean | 169 | 36 | 24·00 | 2·04 | 12·065 --------+-------+-------+--------+----------+-------- By which it appears that the balance in favour of Caithness flagging is 8·865 lbs. The objection to this style of flagging is, that however varied the sizes of the stones selected may be, as they have sawn edges and are very hard to cut with a chisel, a difficulty sometimes arises in finishing rounded corners of footpaths, and against uneven frontages of shops or buildings abutting on the footpath; this is especially the case in old towns. _Blue Lias Flagging._--A blue lias flagging does not make a first-rate pavement, as although it is very cheap, durable, clean, and has many other good qualities, it sometimes wears slippery and is then dangerous to pedestrians; but the Devonian limestone, which is much used in the west of England, has not apparently this defect. _Concrete Footpaths._--These have been tried in this country, but generally without success; the concrete or cement cracks, and in addition to this the paths wear slippery and greasy, and as some time is necessary in order to allow the concrete to thoroughly set before the traffic can be allowed on them, they have not found much favour. In the United States, however, concrete footpaths seem to be made successfully; the following detail particulars of such a foot-pavement will, I think, be of great interest and use.[107] “Concrete footpaths should be laid upon a form of well-compacted sand, or fine gravel, or a mixture of sand, gravel and loam. The natural soil, if sufficiently porous to provide thorough sub-drainage, will answer.[108]