This method of operation can be simplified and more accurate results obtained by equipping each evaporating tank with a one-inch gage glass extending the full height of the tank. The gage glass should be open at the top and connected with the bottom of the tank by a pipe equipped with a valve. Before the tank is filled with cyclone juice the valve is turned off and the gage glass filled with water. Steam is turned on as soon as the pipes are covered and the foam is “broken” quickly without trouble that was experienced in heating the tank filled with cool pulp. The heat is continued while the tank is filled to the desired height with the pulp. The steam is then momentarily turned off and the valve at the top of the gage glass opened to permit the water in the gage glass to equalize in height with the partly concentrated pulp within the tank. The height of water in the gage glass is read by a scale attached, the sample of the pulp taken for examination and the steam again turned on. There is ample time to determine the specific gravity of the sample of partly concentrated pulp and from its volume as obtained by the gage glass to calculate the volume to which the pulp should be evaporated to secure the desired specific gravity in the finished product. The specific gravity of the sample may be taken by any of the methods described in the chapter on “Determination of specific gravity.” More accurate results can be obtained by pouring the sample of pulp as soon as it is taken into a large loosely stoppered flask and holding the flask with constant agitation in a tub of ice water until it is brought to about the temperature of the room. Having determined the volume (when heated to the boiling point) of a batch of cyclone juice or of pulp at any stage of its manufacture and its specific gravity (at 68° F.), each of the last five columns of the table gives a factor by which the volume of the partially evaporated pulp may be multiplied to determine the volume of pulp of the specific gravity given at the top of the column. Since both measurements are taken at the boiling point the question of temperature need not be considered. Table 8.—_Corrections for Specific Gravity and Brix_[19] _Readings at Different Temperatures to 68 Degrees F._ (_20 Degrees C._) Corrections to be subtracted from specific gravity or degrees Brix.