A phosphorescent vacuum tube, the pear shaped bulb containing a mineral sample, with stem and mahogany stand - 13in.high; and a fluorescent vacuum tube on mahogany stand - 13½in.high
A phosphorescent vacuum tube, the pear shaped bulb containing a mineral sample, with stem and mahogany stand - 13in.high; and a fluorescent vacuum tube on mahogany stand - 13½in.high see Front Cover illustration (part lot) (2)
A phosphorescent vacuum tube, the pear shaped bulb containing a mineral sample, with stem and mahogany stand - 13in.high; and a fluorescent vacuum tube on mahogany stand - 13½in.high see Front Cover illustration (part lot) (2)
