Reversing thermometer with Magnaghi frame for taking sea temperatures at depth

Made:
about 1882
designer:
Magnaghi, G. B.

Reversing mercury thermometer frame for holding thermometer when taking sea temperatures at depth, unsigned, c.1882. The frame design is credited to Admiral Magnaghi, Hydrographer to the Royal Italian Navy, and was marketed by Negretti and Zambra from 1885.

Surveyors and navigators struggled to take accurate readings of sea temperature at specific depths. Previous modifications of conventional maximum and minimum thermometers were used in the mid 1800s, but it was not always possible to know at what depth the minimum temperature had been reached. Reversing thermometers attempted to overcome this problem. They incorporated mechanisms that would abruptly capsize the thermometer once it reached the required depth.

Details

Category:
Oceanography
Object Number:
1975-32
Materials:
brass
type:
thermometer frames
credit:
Southampton Oceanography Centre; Institute of Oceanographic Sciences, Deacon Laboratories

Parts

Reversing Magnaghi thermometer frame for holding mercury thermometer

Reversing Magnaghi thermometer frame for holding mercury thermometer

Reversing mercury thermometer frame for holding thermometer when taking sea temperatures at depth, unsigned, c.1882. The frame design is credited to Admiral Magnaghi, Hydrographer to the Royal Italian Navy, and was marketed by Negretti and Zambra from 1885. Rope and iron weight later additions.

More

Surveyors and navigators struggled to take accurate readings of sea temperature at specific depths. Previous modifications of conventional maximum and minimum thermometers were used in the mid 1800s, but it was not always possible to know at what depth the minimum temperature had been reached. Reversing thermometers attempted to overcome this problem. They incorporated mechanisms that would abruptly capsize the thermometer once it reached the required depth.

Measurements:
overall: 2.3kg
Materials:
brass (copper, zinc alloy)
Object Number:
1975-32 Pt1
type:
cages
Image ©
The Board of Trustees of the Science Museum
Box for Magnaghi reversing thermometer frame

Box for Magnaghi reversing thermometer frame

Box for reversing mercury thermometer frame for holding thermometer when taking sea temperatures at depth, unsigned, c.1882. The frame design is credited to Admiral Magnaghi, Hydrographer to the Royal Italian Navy, and was marketed by Negretti and Zambra from 1885.

More

Surveyors and navigators struggled to take accurate readings of sea temperature at specific depths. Previous modifications of conventional maximum and minimum thermometers were used in the mid 1800s, but it was not always possible to know at what depth the minimum temperature had been reached. Reversing thermometers attempted to overcome this problem. They incorporated mechanisms that would abruptly capsize the thermometer once it reached the required depth.

Object Number:
1975-32 Pt2
type:
instrument cases