Democratic Sentinel, Volume 6, Number 7, Rensselaer, Jasper County, 17 March 1882 — THE WORKSHOP. [ARTICLE]

THE WORKSHOP.

Sous ides of the interest in the technicalities of the various industries may be gathered from the fact that Austria alone supports 1,000 technical schools, Italy between 300 and 400, Bavaria 1,600 for girls, Holland 32, Germany a large number, and so on with other European countries. As ▲ cement for leather the following is highly recommended: Common glue aud isinglass equal parts, soaked for ten hours in just enough water to oover them. Bring gradually to a boiling heat and add pure tamin until the whole becomes ropy, or appears like the white of eggs. Buff off the surfaces to be joined, apply this cement warm and clamp firmly. A stone bridge to be built at Minneapolis, Minn., will consist of sixteen eighty-foot spans and four one hundredfoot spans, and including the shorcpieces will have a total length of 1,900 feet. It will support two railroad tracks at a height of nearly sixty feet above the water, and will run diagonally across the river below St. Anthony’s Palls. The cost is estimated at nearly $500,000. Small files are sometimes sharpened with acid as follows: Cleanse from all foreign matter, removing the grease by using a solution of potash and water; then dip in a solution of eight partß water, three parts sulphuric aoid ana one part nitric acid. Take out, wash off, dry and oil. There are other processes, but this is perhaps as good as any, and we do not reoommend this as of much practical value. Wooden bowls, and other ware of this sort, as well as all cross-seotions from tree trunks, and short logs, cut for various purposes, are very apt to crack and split while seasoning. To prevent this completely, the pores of the wood should be well filled with linseed, or some other vegetable oxidizing oil, while it is yet green, and before it begins to show any signs of cracking or checking. This wul completely obviate this inconvenience.

Simple pure white lead ground in oil, and used very thiok, is on excellent cement formending broken crockery ware; but it takes a very long time to harden sufficiently. The best plan is to placj the mended object in some storeroom, and not look after it for several weeks, or even months. After that time it will not part on the line of the former fracture. It resists moisture and a heat not exceeding that of boiling water. The following is recommended as a cement for stoves and steam apparatus: Two parts of ordinary well-dried powdered and one part of borax are kneaded with the requisite quantity of water to a smooth dough, which must be at once applied to the joints. After exposure to heat this cement adheres even to smooth surfaces so firmly that it can only be removed with a chisel. Another cement for steam pipea is prepared, by mixing *430 parts in weight of white lead, 520 of powdered slate, five of chopped hemp aud forty-five of linseed oil. The two powders of the hemp cut info lengths of one-fourth to five-sixteenths of an inch are mixed, and the linseed oil gradually added, and the mass kneaded till it has assumed a uniform consistency. This cement is said to keep better than • ordinary red-lead cement.