Magnaghi Pattern Reversing Thermometer Case
Datelate 19th Century
Object number00056050
NameCase
Mediummetal
DimensionsOverall: 450 × 104 × 72 mm, 1004 g
ClassificationsTools and equipment
Credit LineAustralian National Maritime Museum Collection Gift of CSIRO
DescriptionThe Magnaghi design is a metal frame casing for reversing thermometers. It improved upon the original wooden frame created that was unsatisfactory for manoeuvring at sea. Reversing thermometers require a casing to be held in as they are put overboard by researchers on a vessel. The frame that holds the thermometers in them has gone through many design changes over the decades. The designs use different mechanisms for flipping the thermometers whilst underwater which enables the mercury in the column to break on cue, thus recording temperature at that depth.
Magnaghi’s design included a reversing gear powered by a small propeller set in motion by a brisk reeling up of the frame through the water. It was this mechanism of flipping the thermometers that was modified by many others however kept the bulk of the frame’s design in its integrity. Therefore, Magnaghi’s design was a long running standard piece of equipment in ocean monitoring and research until electrical alternatives became a viable widespread replacement.
SignificanceOcean science practice began in the 19th century, onset by the needs of the first large scale scientific expedition carried out by the Challenger vessel. The late 19th and 20th century was a burgeoning time of scientific innovation, with the creation of tools and equipment to carry out their studies. Compared to the in-depth electrical equipment used in science today, equipment began as much more rudimentary mechanical structures with more manual processes. Wood and metals were the common material constituents compared to plastics and composites in contemporary use. The Magnaghi design was the evolution of a wooden design that used metal for the structure and moving components. The quick succession of innovations simultaneously happening in many countries was a common incurrence during this time. Original materials were cumbersome to use and transport, especially onto research ships. This meant there was always a need to improve a design to be lighter, simpler and more cost effective. Many scientific instruments kept regularly being improved upon, creating a rich history of technological advancements over the century.
