amount of shipping employed exclusively in the coal trade--no less than
5359 vessels carrying coal having entered the port of London alone in
1873, and the average annual quantity of coal exported abroad during the
three years ending 1872 was 12,000,000 tons.

I will not now detain you longer on the subject of the extent and
working of coal, lest I should tire your patience; but before concluding
I should wish to give some account of the uses to which this most
valuable product is applied. The main use of coal, as we all know, is to
produce heat, without which many a paterfamilias would grumble when the
dinner-hour came and he had nothing hot to eat. It not only, however,
supplies heat, but the beauty of the processes for lighting up our
houses is now mainly derived from coal. The immense consumption of coal,
among other things, is in the production of the vapour of water--steam,
by which our thousands of engines on sea and land are made to perform
their various appointed tasks. This production, formed of decayed
vegetable matter, which in ages past nourished on the surface of the
earth, as I have already shown, is again brought forth for our use, and
is a testimony of the goodness and kindness of God in providing for our
wants. By its heat some 10,000 locomotive engines are propelled, and
many hundreds of iron furnaces are kept in work, besides those for other
purposes. It moves the machinery of at least 3000 factories, 2500 steam
vessels, besides numerous smaller craft, and I cannot tell how many
forges and fires. It aids in producing delicacies out of season in our
hothouses. It lights our houses and streets with gas, the cheapest and
best of all lights--London alone in this way spending about £50,000 a
year. It gives us oil and tar to lubricate machinery and preserve timber
and iron; and last, not least, by the aid of chemistry it is made to
produce many beautiful dyes, such as magenta and mauve, and also, in the
same way, gives perfumes resembling cloves, almonds, and spices.