Elger’s Map of the Moon

Forums Moon Getting hold of a beautiful map of the moon Elger’s Map of the Moon

Peter Anderson

I have an Elger’s Map of the Moon on the wall of my observatory in a glass picture frame, that I put over an old watercolour, and it has ‘lived’ on the wall above the desk these last 39 years. I originally bought it in the late 50’s/early 60’s.

Being a lunar observer (occultations mostly), I refer to it regularly for the odd identification and check of terminator etc. etc.

Rukl’s book is good, but this map is ‘in my face’ every night if I need it. 

I also bought ‘The Moon’ by Wilkins and Moore, (the book with the 300 inch map).  The lunar detail really looks impressive, but it is largely unusable. I can believe the complaints that there is a lot of spurious detail.

Now, as far as the mirror reversed images are concerned (and they can be a pain), there are relatively cheap ‘correct view’ prism diagonals available.  Avoid the 45 degree units. Those I have seen are not a great quality and exhibit flares across the field for bright object. Besides they are a pain at high altitudes.  But consider the correct view 90 degree unit. The downside is that the light path is 12mm longer than a standard prism. (the 45 degree one is even longer), and the light path is only about 20mm wide due to the nature of the prism. But for standard eyepieces, say 25mm focus and below, the drop off in light near the edges is not really apparent, and an oldie like me does not have to re-learn directions when I use a lunar map or find a star field or whatever. I have one living on my C14 and another on the 150mm refractor. (The other SCT’s till have the standard prisms.)

I don’t know UK prices but a retail Australian suppler has a standard 90 degree diagonal for $39 and the ‘correct view’ unit for $49. This would equate to around 21 and 26 UK pounds. So they are cheap.