A circular arc, centre D and radius c/2, meets D E in K, and the perpendicular KL gives 2c sin a.
If we draw a line at right angles to TCV, meeting TCV produced in M and parallels through A and B in K and L, the area of the triangle ATB is KL.
This value of 0 is the same for all parabolas which pass through D and E and have their axes at right angles to KL.
The lining of the crucible may be of either magnesite (MgO) or chromite (FeO Cr203) The whole furnace, electrodes and all, rotates about the line KL for the purpose of pouring out the molten FIG.
The Torque Was Measured By Weights 0 And P Suspended By Silk Ribbons Passing Over The Pulleys N And Round The Disk Kl.