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Book, page 351 / 445 bottoms, being thus deprived of their support, drop down. It is possible in this way to effect the discharge of the several carbide-holders by gradual turning of the winch _i_. "The washer B is provided with a thermometer _m_ passing through a sound stuffing-box and extending into the water. "The gasholder C is provided with a scale and pointer, which indicate how much gas there is in it. It is connected with the pressure-gauge _n_, and is further provided with a control thermometer _o_. The gas exit-pipe _q_ can be shut off by a cock. There is a cock between the gasholder and the washer for isolating one from the other. "The dimensions of the apparatus are such that each carbide-holder can contain readily about half a kilogramme (say l lb.) of carbide. The gasholder is of about 200 litres (say 7 cubic feet) capacity; and if the bell is 850 mm. (= 33-1/2 inches) high, and 550 mm. (= 21-1/2 inches) in diameter it will admit of the position being read off to within half a litre (say 0.02 cubic foot)." The directions of the German Association for sampling a consignment of carbide packed in drums each containing 100 kilogrammes (say 2 cwt.) have already been given in the rules of that body. They differ somewhat from those issued by the British Association (_vide ante_), and have evidently been compiled with a view to the systematic and rapid sampling of larger consignments than are commonly dealt with in this country. Drawing a portion of the whole sample from every tenth drum is substantially the same as the British Association's regulations for cases of dispute, viz., to have one unopened drum (_i.e._, one or two cwt.) per ton of carbide placed at the analyst's disposal for sampling. Actually the mode of drawing a portion of the whole sample from every tenth vessel, or lot, where a large number is concerned, is one which would naturally be adopted by analysts accustomed to sampling any other products so packed or stored, and there in no reason why it should be departed from in the case of large consignments of carbide. For lots of less than ten drums, unless there is reason to suspect want of uniformity, it should usually suffice to draw the sample from one drum selected at random by the sampler. The analyst, or person who undertakes the sampling, must, however, exercise discretion as to the scheme of sampling to be followed, especially if want of uniformity of the several
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