heard how much was performed by one steam engine. It sent over this vast building, equable warmth, and supplied all the water that was wanted in every part of the works. It put in motion a mill for crushing the sugar, and other substances used in refining it; and it kept in unremitting action the pistons of a huge

air pump.

After having seen or heard what was done by this steam engine, the great moving power on which all the rest depended, they followed their guide into a sort of out-house, in which the earth of alum was prepared, by adding quick

lime to a solution of it.

They then entered that part of the building where the preparatory operations of cleansing the sugar were performed. They saw in the first place a few workmen with naked arms, and in light clothing, suited to their hot work, stirring with huge shovels in a great pan, the raw brown sugar, such as it is when brought from the West Indies; they were

stirring it up with a small quantity of water, not sufficient to dissolve it. It looked like treacle. This was afterwards poured into earthen moulds, of which there were great numbers in the shape of sugar loaves, such as those of which they had read a description, with a hole at the point, which was turned downwards; and in these moulds it was to be left twenty-four hours to filter. In the course of that time the molasses would pass through into jars beneath the sugar loaf moulds, and the sugar left behind would be in solid lumps, of a light brown colour. Some of the sugar thus purified was put into Lucy's hand; she felt that it was soft enough to be readily crushed. It was now to be dissolved in water, which was heated by having steam passed through it. The earth of alum, which they called finings, was then added to this solution, and thoroughly stirred about by passing currents of steam through it.

This was performed in a great square cistern, which had a double bottom and

sides, with a space left between, sufficient to introduce the steam. The inner bottom and sides were perforated with minute holes; and through these holes the steam passed up into the liquid sugar. They heard a rapid succession of explosions, occasioned by the sudden condensation of the steam; and when the solution became hot, they saw immense volumes of steam rising through it. After this treatment, the syrup was allowed to run into the filter. The filter appeared on the outside like a great square chest; and the inside was divided into parallel compartments, by coarse linen cloth, which was stretched over frames of copper. The liquor was admitted into every alternate cell, and was thus filtered in passing into the contiguous cells on either side, which were empty. The syrup flowed out from the filter a transparent fluid, of a pale straw colour.

They were now conducted to the most remarkable part of the new apparatus, the evaporating pans, in which the water was driven off from the syrup. They were

made with double bottoms, so as to admit steam between the two for heating the syrup; and the pans were covered with domes of copper. These domes communicated with the air pump, the great pistons of which were kept at work by the steam engine. These served to pump out the air, so as to preserve, as far as possible, a vacuum over the liquid. The perfection of the vacuum was shewn by a barometer. The master of the sugar house informed them, that it required one hundred degrees less heat to boil sugar in vacuo than in the ordinary method, and that it was accomplished in less than onefifth of the time formerly requisite.

After having been evaporated, the heat of the sugar was brought to a certain temperature, at which it was found most disposed to crystallise. It was then poured into earthen moulds of the form of a sugar loaf, such as were before described, and in these it was allowed to consolidate. It is then of a tolerably white colour, and is finally purified by being washed

with a solution of the finest white sugar, which is suffered to filter through it. The top and the bottom of the loaves, as being less pure, are then pared off in a turning-lathe, and the loaves are afterwards dried in a stove.

Lucy said, that before she came to the sugar house she had a general idea, from what she had read and heard, that sugar went through several processes of filtering, and boiling, and cooling, and crystallising, before it could be white, and fit for the tea-table; but still she was surprised by seeing the number of the different operations, the size of the vessels, and the power and time necessary. She had not been tired by what she had seen, because she knew beforehand the general purpose, and she had not been puzzled or

anxious.

Harry was delighted at seeing that principle, which he had before so clearly understood, carried into practice with success, in such great works.

"I hope you will now acknowledge,"