Along an unused railway spur, four workmen labored in the shadowy red heat, setting up a platform and steel launchers for the evening fireworks.

At a red heat the litharge and borate of lead are fused, and cause the adhesion of the platinum to the softened glass.

It is better, however, to overheat the crank than to underheat it, providing that the heat in no case exceeds a barely perceptible red heat.