From Thomas A DOBBINS
© . . . . . . . Subject: Mars Nostalgia
Bill and I recently completed a popular nostalgia article for the June 2003 issue of Sky & Telescope about the last perihelic opposition of Mars prior to the Space Age - the opposition of 1956. I have attached a copy of the manuscript for your hopeful enjoyment. Perhaps a bit of the more obscure history will be new to you.
Warmest regards, as ever
© . . . . . . .Subject: Correcting atmospheric prismatic dispersion
I read with great interest Teruaki Kumarmori's success with wedge prisms for eliminating the effects of atmospheric prismatic dispersion in Issue #269 of CMO.
It may interest some readers
to learn that wedge prisms are available in the
These prisms are made from BK7 crown glass. They are all 25.0mm diameter and are available with wedge angles of:
1 degree 56 minutes (nominal deviation 1 degree) Cat. No. F45-555 $45.30
3 degrees 52 minutes (nominal deviation 2 degrees) Cat. No. F45-651 $45.30
7 degrees 41 minutes (nominal deviation 4 degrees) Cat. No. F45-650 $45.30
The late British optical
genius Horace Dall of
Tom DOBBINS (