'Between the years 1811 and 1831, three hundred and forty-eight steamboats were built on the Mississippi and its tributary streams During that period a hundred and fifty were lost or worn out, 'Of this hundred and fifty: worn out 63 lost by snags 36 burnt 14 lost by collision 3 by accidents not ascertained 34 Thirty-six, or nearly one fourth, being destroyed by accidental obstructions. Snag is the name given in America to trees which stand nearly upright in the stream, with their roots fixed at the bottom. It is usual to divide off at the bow of the steamboats a watertight chamber, in order that when a hole is made in it by running against the snags, the water may not enter the rest of the vessel and sink it instantly. 2. This passage is not printed in italics in the original, but it has been thus marked in the above extract, from its importance, and from the conviction that the most extended discussion will afford additional evidence of its truth. 3. Report from the Committee of the House of Commons on the Framework Knitter's Petition, April, 1819. Chapter 30 On Combinations Amongst Masters or Workmen against Each Other 353. There exist amongst the workmen of almost all classes, certain rules or laws which govern their actions towards each other, and towards their employers. But, besides these general principles, there are frequently others peculiar to each factory, which have derived their origin, in many instances, from the mutual convenience of the parties engaged in them. Such rules are little known except to those actually pursuing the several trades; and, as it is of importance that their advantages and disadvantages should be canvassed, we shall offer a few remarks upon some of them. 354. The principles by which such laws should be tried are, First. That they conduce to the general benefit of all the persons employed. Secondly. That they prevent fraud. Thirdly. That they interfere as little as possible with the free agency of each individual.