Hewitt's modification of Clover's 'Portable Regulating Ether Inhaler' - 1901
Date of manufacture:
Barth & Co.
Hewitt's ether inhaler differs from Clover's Portable Regulating Ether Inhaler in the following ways:
a) It has a much wider bore and lower resistance.
b) The mask mount and vaporiser remain stationary so that only a pointer device swivels to change the proportion of air that enters the vaporisation chamber versus that which bypasses it.
c) The facepiece/mask is screwed in place and cannot become detached.
d) The filler does not become rotated to a position of inaccessibility during use.
e) There is no water jacket.