"Tycos" micro-barograph recording barometer
Datecirca 1920
Inventory NumberDW0640
ClassificationBarometer
Subject
Maker
Short and Mason
1875 - 1918
Supplier
Taylor Instrument Companies
1851 - 1992
User
Department of Geology and Geography, Harvard University
1890 - 1961
Cultural Region
Place of Origin
Dimensions22.6 × 31.6 × 17.8 cm (8 7/8 × 12 7/16 × 7 in.)
Material
DescriptionA recording barometer consisting of brass parts on a black metal moulded platform, with a glass and black metal cover.
On the metal platform, there is a center section of brass. Here, there are fourteen extremely thin metal capsules partially evacuated of air, stacked in series, and connected by a series of levers to a pen-arm. This arm is positioned so that it can inscribe a line onto the paper graph wound around the brass drum, which is rotated slowly by internal clockwork.
The paper graph is divided into columns for the days of the week and the hours of the day. The rows of the graph correspond to a scale of barometric pressure in inches, running from 28.50 to 31.00 in.
There is a small brass cylinder to the side of the drum which contains a glass bottle of purple ink, with a stopper and dropping mechanism. There is also some cotton stuffed into the brass holder.
On the metal platform, there is a center section of brass. Here, there are fourteen extremely thin metal capsules partially evacuated of air, stacked in series, and connected by a series of levers to a pen-arm. This arm is positioned so that it can inscribe a line onto the paper graph wound around the brass drum, which is rotated slowly by internal clockwork.
The paper graph is divided into columns for the days of the week and the hours of the day. The rows of the graph correspond to a scale of barometric pressure in inches, running from 28.50 to 31.00 in.
There is a small brass cylinder to the side of the drum which contains a glass bottle of purple ink, with a stopper and dropping mechanism. There is also some cotton stuffed into the brass holder.
Signedon brass plate: Tycos / MICRO-BAROGRAPH / BY / SHORT & MASON / LONDON / MADE IN GT BRITAIN. / No. E29730
Inscribedengraved: Compensated for temp.
Curatorial RemarksBrass works in glass and black metal frame case. Uses 6.75 inch-wide charts, seven day clock. Engraved "compensated for temp."
FunctionBarographs such as this use the partially evacuated metal capsule of aneroid barometers, which are very sensitive to pressure changes, and contract or expand in accordance with outside air pressure. Because the movement of a single aneroid capsule is extremely small, often there are many stacked in series to amplify the change. In this case, there are fourteen, which is a relatively high number. These capsules are linked by a series of gears or levers to a metal arm with a scribe or pen tip so that the vertical position of the pen corresponds with the atmospheric pressure as read by the capsules. The pen then draws a continuous record of atmospheric pressure onto a chart of paper or smoked foil, mounted on to a drum which is rotated by internal clockwork. This instrument provides one week's wort of recordings per revolution of the drum.
Because atmospheric pressure also corresponds to changes in altitude, barographs can also be used to track elevation.
Because atmospheric pressure also corresponds to changes in altitude, barographs can also be used to track elevation.
ProvenanceDavid Wheatland purchased from the Harvard Geography Building (Institute of Geographical Exploration), February 1959.
Davis & Son
Date: 1843-1873
Accessories: small metal key
Object number: 1998-1-0606
Richard Frères
Date: circa 1890
Accessories: 1 completed graph, 1 bottle of ink, ke, brass gear, leather carrying strap
Object number: 1998-1-1315
Sterling P. Fergusson
Date: date 1888
Accessories: Instruction pamphlet
Object number: 1996-1-0088
Seth Thomas Clock Company
Date: circa 1900
Accessories: Case and rest of instrument on B7-I shelf
Object number: 1996-1-0194b
Julien P. Friez & Sons
Date: circa 1920
Accessories: hair recording hygrometer
Object number: DW0639
Friez Instrument Division, Bendix Aviation Corporation
Date: 1943-1950
Accessories: lid; stack of aerograph paper; metal case
Object number: DW0446
