A comparative test is made by taking an equal quantity of each kind of paper, boiling in similar quantities of water for the same period, and adding the same amount of tannic acid solution, and comparing the results. The amount of mechanical wood may be estimated by the depth of colour, but this is very difficult, as may be proved by comparing the results obtained on papers containing 40 and 70 per cent, of mechanical wood respectively. The uncut boards should be perfectly flat in order that ruling, printing, and cutting may be executed with accuracy. Being a quality conscious organization, the premium quality of offered printing, coating and lamination machines is never compromised. The tests by the folding machine, being conducted on a very narrow strip, are only moderately reliable. Colouring Matters.-The tests for colours should be for the purpose of discovering whether they are reasonably fast to light and when wetted.
The comparisons can be brought to a numerical basis, but apparatus which would seldom be used is required for that purpose. The second novel application of cork is for storing a portion of the energy of the recoil of cannon, for the purpose of expending it afterward in running them out. The result of the explosion of gunpowder in a gun is to drive the shot out in one direction, and to cause the gun to recoil with equal energy the opposite way. In the little ram here represented, this action, which it has taken so long to describe, is repeated one hundred and forty times in a minute. One extreme example would be an angle profile with relatively short legs (a single 90° bend angle) requiring only a few passes of tooling. Pour off into a test tube, cool, add a few drops of a 2 per cent, solution of tannic acid.
If the test tube is shaken up the opalescent appearance of the liquid indicates the presence of resin. As soon as the solution is cool, pour it into a test tube half full of distilled water, and the resin will appear as a ring, whitish in colour, at the junction of the two liquids. The spirit will boil before the water reaches boiling point, and in a short time the resin will be dissolved. When air is used for this purpose, the air-vessel has to be filled, and, with most kinds of water, the supply has to be kept up while the ram is working, because water under pressure absorbs air. To restrain the motion of the gun, “compressors” of various kinds are used, and in this country, for modern guns, they are generally hydraulic, that is to say the force of recoil is expended in causing the gun to mount an inclined plane, and, at the same time, in driving a piston into a cylinder full of water, the latter being allowed to squeeze past the piston through apertures, the areas of which are either fixed, or capable of being automatically varied as the gun recedes; or else the water is driven out of the cylinder through loaded valves.
These machines are exceedingly useful for rapid comparisons of papers, the tests being made at the same time. The rotary presses in use at the present time are indeed wonderful specimens of mechanical ingenuity, all the various operations of damping (when necessary), feeding, printing (both sides), cutting, folding, pasting, wrapping (when required) and counting being purely automatic. An aqueous extract of the paper may be treated with the iodine solution, and if a comparative test is to be made, it is necessary to work on each paper with identical quantities of water for boiling, and iodine solution for testing. Bursting Strain.-For quick comparative tests there are a number of machines to choose from. The substance of the defense in the case is that there are certain specific differences between the button-feeding mechanisms in the two machines, and also certain specific differences between their sewing mechanisms; and hence that there is no infringement. For this, our team members frequently communicate with the clients to know about their specific requirements. The paper is tested at the same time for squareness.
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