I am sure it will gain both in beauty and strength. It is true
that the divergence of these radii recurs as a difficulty, in getting
the rails on upon the bolts; but I thought this fully removed by the
answer you first gave me, when I suggested that difficulty, to wit, that
you should place the rails first, and drive the bolts through them,
and not, as I had imagined, place the bolts first, and put the rails on
them. I must doubt whether what you now suggest will be as good as
your first idea; to wit, to have every rail split into two pieces
longitudinally, so that there shall be but the halves of the holes in
each, and then to clamp the two halves together. The solidity of this
method cannot be equal to that of the solid rail, and it increases the
suspicious parts of the whole machine, which, in a first experiment,
ought to be rendered as few as possible. But of all this the practical
iron men are much better judges than we theorists. You hesitate between
the catenary and portion of a circle. I have lately received from Italy
a treatise on the equilibrium of arches, by the Abbe Mascheroni.
Pages:
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904