h 10 parts In making a piece of glass tubing the assistant places a phosphates, fat or grease, sometimes animal fiber, and always of cow’s hair, add 600 parts of water into which 10 to 15 parts ball of glass against the end of the glass cylinder by aid of that very indefinite compound ‘‘ dust.”… … some of the continental manufac- to resist great pressure or changes Fie. 1.—COOLING GLASS TUBES. turers to wash the surface of the of temperature, they are annealed sheets of their finest kinds with with great care. They are some- warm water after they are dry so as to remove the extra- dough of…
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