This is a beautifully simple scientific instrument. Its only moving part allows it to be set at the correct angle for the latitude of the recording site. Once that is set, the instrument records the duration of bright sunshine across each day; this requires that a new card be inserted behind the glass sphere, in one of three positions depending on season (and hence on the height of the sun in the sky). Whenever the sun is shining, the sphere focuses its rays onto the card, causing it to char in that spot; the number of hours of sunshine can be determined by measuring the resultant trace.

Although other more sophisticated instruments are now used to record sunshine, this highly reliable type of solar recorder is still used alongside them at weather stations in many countries, including Australia. As they have been available since the 1880s, their continued use can provide long runs of comparative data.

The sunshine recorder was designed by John Campbell and improved by George Stokes, both in the UK. It was made by the firm run by Rudolf Fuess sometime after he moved to his new premises in Steiglitz, Berlin, in 1892. Originally installed at Sydney Observatory, it was passed on to the New South Wales Bureau of Meteorology sometime in the early twentieth century. It was not used for many years and was donated to the Powerhouse Museum by J. M. Moss of the New South Wales Bureau of Meteorology in 1963. When Sydney Observatory became a part of the Powerhouse Museum in 1981, the instrument was reunited with others in the Observatory's collection.

Geoff Barker, Assistant Curator, March 2007
Amended by Debbie Rudder, Curator, November 2008

References
Mappes, T., 'Petrografisches Mikroskop, R. Fuess nach H. Rosenbusch', 2003 - 2007, cited at http://www.musoptin.com/fuess_rosenbusch_1875.html, 29 October 2007
Burchard, Ulrich, Mineralogical Record, November-December 1998, http://findarticles.com/p/articles/mi_qa3672/is_199811/ai_n8814710/pg_34

http://data.piercecollege.edu/weather/duration_sunlight_recorder.html
http://en.wikipedia.org/wiki/Campbell-Stokes_recorder
http://www.bom.gov.au/climate/averages/climatology/sunshine_hours/definition.shtml

The instrument was invented by John Francis Campbell and improved by Sir George Stokes, both in the UK.

Heinrich Ludwig Rudolf Fuess was born in Germany in 1838, and from 1853 to 1857 he worked with Hermann Pfaff in Goettingen and visited the local university where he heard lectures on mathematics and physics by Dr. Wilhelm Eduard Weber and on optics by Dr. Johann Benedict Listing. When he finished studying, he started working with Hermann Pfaff in Gottingen and later worked with Hugo Schroeder in Hamburg.

In April 1865 Rudolf Fuess started his own company in Berlin, making scientific and mathematical instruments. The company did well and in 1873 moved to 108 Alte-JakobstraÃ?e and in 1875 merged with the company of J.G. Greiner. In 1892 the rapidly growing company moved to Berlin-Steiglitz where it was praised for the quality of its research into polarizing microscopy. The company continued to produce quality equipment in the 1920s even though Fuess himself had died in 1917.

References
Mappes, T., 'Petrografisches Mikroskop, R. Fuess nach H. Rosenbusch', 2003 - 2007, cited at http://www.musoptin.com/fuess_rosenbusch_1875.html, 29 October 2007
Burchard, Ulrich, Mineralogical Record, November-December 1998, http://findarticles.com/p/articles/mi_qa3672/is_199811/ai_n8814710/pg_34

The sunshine recorder was originally installed at Sydney Observatory on Flag Staff Hill.

Sunshine or solar recorder, Campbell--Stokes, glass / metal, used at Sydney Observatory, made by Rudolf Fuess, Steiglitz, Berlin, Germany, 1892-1905

A sunshine or solar recorder consisting of a glass sphere mounted on a brass quadrant with a latitude adjustment; this is set for Sydney's latitude. The quadrant also supports a curved brass card or form holder that sits directly behind the glass sphere. The quadrant is mounted on a rectangular cast alloy base.

In use, a card is inserted each day, its position being selected according to the season (as the sun is higher in the sky in summer than in autumn or spring, when it is higher than in winter). Whenever the sun is shining, the glass sphere focuses its rays onto the card, which changes colour at that spot as a result of charring. The resulting trace, which is continuous on a sunny day and discontinuous if there are periods of heavy cloud, can be used to assess the number of hours of sunshine.

Made: Fuess, Rudolf; Berlin, Germany; 1895 - 1905


Used: Sydney Observatory; Observatory Hill

Engraved into the brass at the base of the brass quadrant 'R FUESS BERLIN - STEGLITZ'.

H7353

1895 - 1905

230 mm

210 mm

146 mm