Lead-Glass “Bowl”

Ref. L5

This is a lead-Glass radiation protection “bowl”, dating probably to the last years of the first decade or the first years of the second decade of last century, as can be seen from the above drawing, (as well as from other drawings), reprinted from “Lehmann’s med. Atlanten, vol. 5 – Atlas Typischer Röntgenbilder – 2nd Ed. By Rudolf Grashey, 1912”.

In the above drawing, to the left, the “bowl” is used with a gas discharge tube. But such “bowls” remained in use with large-bulb Coolidge tubes until the advent of the small-bulb tubes fitted with a heat radiator, and enclosed in a more radiation-tight spherical lead-glass housing, probably in the early twenties.

This “bowl”, of unknown make, is 8” (20 cm) high, with an upper opening of 9” (23 cm), an underside opening of 4.5” (11 cm) and a weight of 10 lbs (4.6 Kg). Note the 4 equidistant vertical lines etched on the outer wall of the “bowl”, symmetrically placed on either side of the deep notches, intended to help visually placing the focal spot of the tube in the geometrical centre of the “bowl”.

In the drawing to the right, a “hemispheric bowl” is placed at a 45 degrees angle around the X-ray tube bulb, parallel to the plane of the anode target. (Picture from “Précis de Radiodiagnostic - Technique et Clinique”, F. Jaugeas , 1918, Masson et Cie, where all positioning pictures are shown with a hemispheric bowl).