Letter to the Editor
I feel duty-bound to point out that, contrary to the statement in the otherwise excellent lead article on the 3-mm first-light at the Australia Telescope Compact Array in the 2001 February newsletter, this is not the first 3-mm interferometer in the Southern Hemisphere. I believe that this honour belongs to a portable instrument built by John Archer and Norman Labrum in order to observe solar limb intensity profiles during the solar eclipse of 1976 October 23, which produced totality over a path sweeping through Victoria and southern NSW. The resulting profile was published in Proc ASA 3, 256, 1978, and I assume there is further material in John Archer's Sydney University Ph.D. thesis (1977). There is a photo of Labrum with the interferometer on page 173 of the book "Solar Radiophysics" (McLean and Labrum, Cambridge University Press, 1985). Labrum also carried out single-dish 3-mm observations of the eclipse with a 1-m telescope from Stawell in the Grampians in Victoria, and my resources don't say whether the portable interferometer was located there or somewhere else.
I hasten to add that I had no involvement in this experiment (I am, after all, far too young), but I do remember the eclipse as I was batting low in the order for an ANU 5th or 6th grade cricket team in the suburbs south of Canberra at the time and my otherwise brief innings was interrupted by an early and lengthy tea while we waited for the partial eclipse (there) to pass.
Norman Labrum with the 3-mm interferometer. Reproduced with the permission of Cambridge University Press, from "Solar Radiophysics", 1985, edited by Don McLean and Norman Labrum (Cambridge University Press).
Stephen White
University of Maryland
(white@astro.umd.edu)