Altimeter

Geophysics Collection · Physics

Accession Number: 2015.ph.659

Description:

This is a cylindrical instrument contained inside a leather case with a long strap.

The leather case is cylindrical, with an open top and bottom. Looped around the exterior of the case through two loops is a narrow leather strap with a buckle at one end; the belt end of this is broken and repaired with a piece of green tape. Additional buckles are fixed to the side of the instrument, as are some additional leather straps; these are broken off at the base of the cylinder. These are likely the remnants of straps that apparently passed under the instrument to provide support underneath the instrument and allow it to be removed. The top of the case has a narrow lip around the rim and a circular metal piece inside of this into which the top edge of the instrument fits. When contained in the case, the face of the instrument is visible.

The altimeter consists of a short black-lacquered brass cylinder, with a circular face covered with a clear plastic cover. The face has a double circular scale around the rim, displaying measurements from ‘0’ to ‘9700’, labelled in thousands and hundreds. At the centre of the face, on top of the cover, there is a ridged brass dial. A thin metal indicating needle is attached to the base of this and can be turned by turning the dial. At the top of the face, a thin filament at the top of the face moves between + and – marks to indicate the accuracy of the rotating needle’s position.

Primary Materials: Brass, Leather, Glass, Other Metal.

Markings:

On the face: “Precision Altimeter”, “Patented”, “System Paulin”, “Stockholm”
“MADE IN SWEDEN BY C. E. JOHANSSON, ESKILSTUNA”.

Stamped into the metal base of the instrument: “MADE IN SWEDEN”, “A3335”, and “PAT’D U.S.A. SEPT. 9-19 APR. 18-26”

Dimensions (cm):

Without case: Diameter = 12.3, Height = 6; with case: Diameter = 14.6, Height = 8.5.

Function:

This is a device for measuring altitude, likely intended for use in the field.

Condition:

Good: The leather case is in very poor condition; it has red rot, is dry and brittle, and is separated into several pieces. There are also several pieces of green canvas tape on parts of the leather case from attempts to repair it; however, they have dried out and no longer have any active adhesive. Some parts of the case described in the original entry (2015) are missing. These comprise a wooden disk that forms the lid, a leather disk that covered the lid, the main structure of the case with the strap still attached, the base for the case, and a miscellaneous leather strap which may be part of the lid.

The instrument is in good condition and appears to be operable, although not accurate. The plastic cover is slightly cloudy. The black surface of the metal case is worn off, particularly around the top rim of the instrument and on the base. There are some small corrosion-type spots on the face, which is otherwise in good condition.

Manufacturer: C. E. Johansson, Eskilstuna, Sweden.

Date of Manufacture: c. 1926-1940

Provenance:

Department of Physics, University of Toronto

Additional Information and References:

A similar instrument is held by the National Museum of American History and is described here.

  • Donated to UTSIC