And the effect is cumulative.

The manufacture of iron being stimulated, all persons concerned in that great manufacture are well off, have more to spend, and by spending it encourage other branches of manufacture, which again propagate the demand; they receive and so encourage industries in a third degree dependent and removed.
'It is quite true that corn has not been quite so cheap during the present year.

But even if it had been dearer than it is, it would not all at once arrest the great trade which former cheapness had created.

The "ball," if we may so say, "was set rolling" in 1869 and 1870, and a great increase of demand was then created in certain trades and propagated through all trades.

A continuance of very high prices would produce the reverse effect; it would slacken demand in certain trades, and the effect would be gradually diffused through all trades.