| The manometric
flame apparatus was developed by Rudolph Koenig in 1862. It consisted
of a small gas flame whose height was modulated by variations in air pressure
impinging on a flexible membrane. The resulting capsule could be mounted
on an organ pipe with the membrane facing inward. The flame was observed
in a rotating mirror that moved the image of the flame constantly to one
side, thus providing a time base.
This "open organ pipe with three manometric flames ... 45 francs" at the University of Toronto, is item number 237 in the 1889 Koenig catalogue.
| This pipe, with a lead end flap to enable
it to be used as either an open or a closed pipe, had a manometric flame
capsule mounted in the middle to show that this point is a node when the
pipe is open, and has some oscillating air motion when the pipe is closed.
The pipe is at the University of Toronto, and is not listed in the 1889 catalogue. It was certainly part of the collection bought by Toronto after the 1876 Centennial Exposition in Philadelphia.
|| This open pipe has two manometric flames. The scale can
be obtained from the fingers holding the pipe upright. The apparatus is
not in the 1889 Koenig catalogue.
REF: Thomas B. Greenslade, Jr., "The Rotating Mirror", Phys. Teach, 19, 253-255 (1981)