With every operation connected with the fashioning of the earth, the result is the same. The first step is, invariably, the most costly one, and the least productive. The first drain commences near the stream, where the labour is heaviest. It frees from water but a few acres. A little higher, the same quantity of labour, profiting by what has been already done, frees twice the number. Again the number is doubled; and now the most perfect system of thorough drainage may be established with less labour than was at first required for one of the most imperfect kind. To bring the lime into connection with the clay, upon fifty acres, is lighter labour than was the clearing of a single one, yet the process doubles the return for each acre of fifty. The man who needs a little fuel for his own use, expends much labour in opening the neighbouring vein of coal; but to enlarge this, so as to double the product, is a work of comparatively small labour. To sink a shaft to the first vein below the surface, and erect a steam-engine, are expensive operations; but these once accomplished, every future step becomes more productive, while less costly. To sink to the next vein below, and to tunnel to another, are trifles in comparison with the first, yet each furnishes a return equally large. The first line of railroad runs by houses and towns occupied by two or three hundred thousand persons. Half a dozen little branches, costing together far less labour than the first, bring into connection with it half a million, or perhaps a million. The trade increases, and a second track, a third, or a fourth, may be required. The original one facilitates the passage of the materials and the removal of the obstructions, and three new ones may now be made with less labour than was at first required for a single one.