Early Barograph by Richard Bros.
The small wood and glass cased instrument measures 7 inches long by 4 inches wide and 5 inches high. A series of 5 vacuum chambers are used to detect changes in barometric pressure, their movement being amplified by levers to record a span of 28.5 to 31.0 mm Hg on a 2 1/2 inch chart. The mechanism is mounted on 2 pairs of turned brass pillars. An 8 day clock is mounted within the small chart drum. The original double ended clock key is used both to wind the clock and to adjust the barometer. The original V-shaped ink trough is included, as well as a home made replacement device
used by the previous owner, in which a small length of a ball point pen ink tube is fitted into a small plastic base with a marker head. Both the original ink trough and the new replacement simply slip onto the end of the arm and are instantly replacable. The old ink trough tips work well with the proper ink/glycerine mixture, but requires frequent cleaning and can be messy.
The brass base plate of the instrument is marked "Richard Freres, Constructeurs, Brevetes, PARIS". An ivory nameplate on top of the case reads "Hazebroucq, Ingenieur - Opticien, 23 Rue de la Paix, Paris".
In addition to being an impressive display piece, the instrument appears to be in fine working order. It has been in use on my desk for the past 10 days and has closely tracked several accurate barometers and a modern barograph. The clock is also keeping good time. 36 unused charts are included, as well as 71 photocopied charts, which the previous owner had been using, to save the originals.
Jules Richard (born 1848) developed many meteorological instruments. The French firm of Richard Freres produced the first small, light, and inexpensive recording instruments in the 1880's, marking the end of the huge and mechanically complicated meteorographs of the 19th century. Richard's new instruments were even adapted for high altitude recording from kites and balloons. See Middleton, Invention of the Meteorological Instruments.
Price: (sold)
Items reserved by email will be held 10 days and shipped upon receipt of your check.
Contact: Richard Van Vleck - Email: richard@americanartifacts.com
© 2006, American Artifacts, Taneytown, Maryland.
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