Instruments:
 –4 inch heliograph (1910 – 1958)
–Lyot Heliograph (1958 – ?)

Duration: 1910 – ?

Publication:

Description:

History:

* 4 inch heliograph. Since 1910 two photos of the Sun per day in white light (weather permitting) has been taken. These photos were sent to the Royal Greenwich Observatory. Similar photos are taken at Greenwich, supplemented with photos from Kodaikanal and Mount Wilson. It provides a continuous record of the positions, motions and developments of sunspots and faculae.
* Lyot Heliograph. Installed in 1958. Every minute a photo is taken on 35mm film at wavelength 6563 Angstrom (?) the Helium Alpha line (?). This forms part of the world wide flare patrol.

Sources:

-Laing, J.D. (ed.), The Royal Observatory at the Cape of Good Hope 1820 – 1970 Sesquicentennial Offerings, p.32.