heliograph_4i

Heliograph

4  inch (10 cm)

Index:

Summary; History; Current; Technical; Sources; Links; Gallery:

In brief

Important  Contributions:

Description:
Used  since 1910 to take two photographs of the
sun per day (weather permitting). The photos were sent to Royal Greenwich  Observatory.

Historical Background

Owner:
Cape Observatory

Where Located:
Cape Observatory

Current Information

Present  Location:
SAAO

Owner:
SAAO

Status:
Used occasionally for public viewing.

Condition:
Operational

Technical Details

Type: Reflector / Refractor
Aperture: 4 inch (10.16 cm) giving an 8-inch (20.32-cm) picture
Focal Length:
Mirror / Lens:
Mounting:
Attachments:
Manufacturer:
Operational History:
Building:  The heliometer stood in the dome which first housed the 7-inch Mertz telescope. A unique feature of the dome is that it revolves on six cannon balls. [Koorts p. 52]

Sources

Link to the Main Bibliography Section and more information about Sources.

Documentation:

Pictorial Sources:

Bibliography:

  • Koorts, W.: The 1882 transit of Venus: The British expeditions to South Africa; MNASSA April 2004, Vol. 63 nos. 3 & 4, pp. 34 – 57.
  • Laing, J.D. (ed.), The Royal Observatory at the Cape of Good Hope 1820  – 1970 Sesquicentennial Offerings, p.32.

 

Links

Gallery

Heliometer_10c4i_-01r
Reginald de Kock at the eyepiece of the Heliometer.
Source: A.S.S.A. Archives: Peter Smits Collection

Heliometer_10c4i_Obs-01r   Heliometer_10c4i_Obs-02r
The Heliometer Observatory. Sketches are part of a compilation of sketches concerning the Cape Observatory.
Left hand sketch published by “The Graphic”, 27 August 1892. Courtesy of Africana Museum, Johannesburg. Source: Moore
Right hand sketch published by “The Cape Times”, 19 September 1908. Source:Warner, Astronomers