Sharing some photographs of a 1902 Mabie Todd & Bard silver eyedropper with the ink flow control valve.
Engraving on the barrel:
The Swan Pen
PAT. FEB 8 81. FEB 21.82. MAR 6.88
Mabie Todd & Bard New York
Albert S Waller
In recognition of
Mabie Todd & Bard
As per the book, of Steve Hull, the ink control valve is illustrated below.
I'm not sure that it is more of a marketing claim than a precision ink flow control!
Anyone had good experience of using this ink control stopper?
NB. The BCHR slip cap is not original, i'm sure looking at advertising of the time it would have been silver overlay.