37^ Improvement in Rail Roads ; 
There is a small groove in the whole length of the exte- 
rior of each ping, to admit a wire to pass to its extremity, 
to draw the plug out if broken by any accident, also 
to admit the expansion of water, in case of severe 
frost. 
The blocks or sleepers, EFG, on which the tram-plates 
are placed, should by no means be less than one hundred 
and twenty pounds each in weight, but should be heavier 
on some kinds of ground: the depth of the hole for the 
plug should be three inches, and worked according to the 
inclination of the plug, for which purpose the stone-mason 
should have a standard cast-iron guage ; there should be 
projections, K, cast with the flanch or outside edge of the 
tram-plate, as shown at fig. 7? to make the plates lie firm 
on their sleepers. 
Fig. 10, is a section of one of the ends of a tram-plate, 
In which H shows the flanch or upright edge, I the flat 
part or sole on which the wheels of the waggons run, D 
one of the plugs, K the projection behind the flanch to 
make the plate lie firm on the blocks. 
General Observations. 
The advantages of laying plates on the above principle 
are obvious ; the blocks being put in their places never 
sink below their intended level, the act of driving either 
nail or plug, (which requires a considerable degree of 
force, and too frequently destroys the level of the road,) 
being here unnecessary. In the common mode of mak- 
ing rail-roads, from the irregularity of nails, particularly 
in forming their heads, few can be driven exactly even 
with the plate, and they are perpetually obstructing the 
passage of the waggon ; the workmen frequently not pro- 
portioning their holes and plugs to the hole in the block 
also occasions considerable breakage ; the exertion ne- 
cessary to fix a rail or plate completely is great, and 
