The successful operations for converting steel into various kinds of instruments, depends very much upon manual skill. The mechanics are united in trades' unions of great power, and have exercised an influence over the manufacturers of the town of a very injurious nature. At one period, the razor-grinders and superior mechanics in several branches, were able to earn as much as five and six, and even ten, pounds a-week. At that period, when they had almost a monopoly of the cutlery trade, on a very trifling excuse they would decide on taking a holiday, or, as it is termed, "playing." Strikes for higher wages generally took place whenever any good orders from foreign markets were known to have reached the town. By these arbitrary proceedings, arising from an ignorance of the common principles of political economy, which it is to be hoped that the spread of education will remove, the Sheffield cutlery trade has been seriously injured. A few years ago large numbers of the cutlers emigrated. Further depression was produced by the rivalry of Birmingham in the electrotype process, which has, to a considerable degree, superseded the Sheffield plate and other trades, the latter town being better placed for the foreign trade, while the workmen are less turbulent. Beside cutlery and Sheffield plate, Britannia metal, and other similar ornamental and domestic articles, a good deal of heavy ironware is made in Sheffield. We may notice the fire-grates, stoves, and fenders, of which all the best, wherever sold and whatever name and address they bear, come from Sheffield. In this branch of manufacture a great deal of artistic taste has been introduced, and many scientific improvements for distributing and economizing heat. The firm of Stuart and Smith, Roscoe Place, distinguished themselves at the Great Exhibition, by producing a series of beautiful grates, at prices between two pounds and one hundred guineas. There are some establishments for the manufactory of machinery. Within the last year or two Sheffield has enjoyed a revival of prosperity, especially in the article of edge tools. The mechanics of Sheffield are a very remarkable and interesting set of people, with a more distinct character than the mechanics of those towns which are recruited from various parts of the country. They are "Sheffielders." A public meeting at Sheffield is a very remarkable scene. The rules of public business are perfectly understood and observed; unless in periods of very great excitement, the most unpopular speaker will receive a fair hearing. A fair hearing does not express it. The silence of a Sheffield audience, the manner in which they drink in every word of a stranger, carefully watching for the least symptom of humbug, and unreduced by the most tempting claptrap, is something quite awful.