"Forgive Me, Old Man!"
"Right!"
The two were standing now before the cylindrical furnace containing the mixture of silicates and other ingredients from which Tom Swift hoped would emerge a glass as flexible as rubber and as strong as steel. The thermometer on the front stood at twenty-one degrees Centigrade.
They Looked at the Thermometer
"She's just right," muttered the inventor, consulting a complicated chart hanging on the wall. "Now we'll see!"
The asbestos-coated door clanged open. Tom drew out a shallow tray, the contents of which were buried in a black powder.
"Charcoal!" he explained, setting the pan on a table. "It prevents any rapid temperature change. Even common glass must be cooled slowly or it becomes as brittle as peanut candy."
