Profile: Greers Ferry Glass Works is a manufacturer of hydrometers and thermometers. Our hydrometers ranges from coal oil hydrometers and Gay Lussac hydrometers to ballasted precision hydrometers for nuclear submarines and hydrogen peroxide hydrometers for missile fuel. Cannon-Fenske routine viscometers are designed for transparent liquids and it is a widely used type of glass capillary kinematic viscometer tube for measurements of fluids with Newtonian flow behavior. Our centrifuge tubes are manufactured with borosilicate glass.