This advantage is especially observed in some cases in which the charge of the furnace is liable to attack the containing vessel at high temperatures, as it is often possible to maintain the outer walls of the electric furnace relatively cool, and even to keep them lined with a protecting crust of unfused charge.
Zirconia, when heated to whiteness, remains unfused, and radiates a fine white light, which suggested its utilization for making incandescent gas mantles; and, in the form of disks, as a substitute for the lime-cylinders ordinarily employed in "limelight."
The whole wing is consequently, although essentially avine, still reptilian in the unfused state of the metacarpals and the numbers of the phalanges.
- Ambulacrals alternating and unfused, groove uncovered by ventral arm-plates.
It demonstrates the os acromiale, an unfused acromial apophysis.