METHODS OF CASTING TEST BARS FOR THE A. F. A. 547
remaining in the basin and runners flowed out readily to pig beds having a lower level than the pouring basin and runners as seen at C, Fig's. 142 and 143, thus leaving the moulds disconnected to be removed singly from their easting pits after the gate connections between the 11 asks at G were broken. The basin A being, as shown, one foot wide and deep, gives a body of fluid iron weighing about three tons, uniform in temperature. And when it is said that from the moment the inlet plate II was lifted to the time the 192 test bars and two chill blocks, all weighing* when cleaned 3,780 pounds, were all poured scarcely twenty seconds passed and no bars were lost, all will realize the success achieved.
Casting half the bars in dry sand cores was done for the purpose of making a comparison between the effeeis of a green and dry sand mould and to give greater completeness to the results. The dry sand bars we're made in cores instead of iron flasks, for the reason thai, it was thought that some of the shops the work was assigned to might not be in a position to dry the dry sand moulds, but could handle the cores.
In making the cores it was very desirable to have them of a character that would crush easily when the bars commenced to contract, as anything preventing this might strain the bars internally so as not to give a true test. The1 author adopted the following mixture f <>r 111,'iking 11 )e eores:
i part lake, river, or bunk sand,
3 parts lint' silica, or crushed sand,
i part, rosin to '.15 parts of sand,
i part <>f (lour to u? parts of sand
i -part, i'.hitrose to ;io parts sand. Wet bnlanee with water.rface of the metal in the basin | A. Two risers were carried from the two outside