Looks like a target list for a pair of opera glasses. Not having any of the latter, I thought it would be interesting to see how many of the listed 53 craters and mountains I can see with my 8x50s. I'm assuming I can manage the Seas, Gulfs and Marshes
This came from 'Astronomy with an Opera-Glass' by Garrett Putman Serviss [1851-1929]. Once I had an old copy of that book and used it as a basis to write an article for Popular Astronomy / January-March 2003. page 25-26, under Instruments.
At that time did some experiments using opera-glasses and listed positive and negative points in using them. I do still have a copy of the printed article, although not the book. You may locate a copy of the complete book by Serviss on-line by searching for the title. regards maf
Last edited by michael feist on Thu Jan 14, 2021 3:11 pm, edited 2 times in total.
Thanks for the info. I'll see if I can find the book. I guess it lists stars and galaxies and wotnot.
One advantage of my "experiment" is that I can probably do it from inside, a plus at this time of year! Not that there's any sign of clear weather in the BBC forecast for the next two weeks. I suspect the next time I see Jupiter and Saturn it'll be in the morning sky!
SkyBrowser and Mike, it's very interesting reading back through historical astronomy books. I've managed to find the book referred to on Google Books, which is free, as the book is out of copyright presumably. The link is here.
I'm actually intrigued, and may well give this a go, SkyBrowser. I'm tempted to try it with an 8x23, closer to the power of opera glasses, which presumably would be between 3x to 5x?
When the book was published, it was a Newtonian universe, the galaxies were regarded as clouds of gas in our galaxy, and the Sun was burning like a piece of coal, not nuclear, etc. The author would have been astonished to know what astrophysics has revealed about the Universe since then.
jeff.stevens wrote: ↑Thu Jan 14, 2021 8:30 pm
I'm actually intrigued, and may well give this a go, SkyBrowser. I'm tempted to try it with an 8x23, closer to the power of opera glasses, which presumably would be between 3x to 5x?
Not sure - we don't go to the opera enough to own a pair! I do, however, have a pair of the Vixen 2.1x42s so I might try with them, though I suspect that's not enough magnification for most of the objects.
brian livesey wrote: ↑Thu Jan 14, 2021 9:24 pm
The author would have been astonished to know what astrophysics has revealed about the Universe since then.
I do have faint recollections of reading about some early nineteen century Frenchman who said (more or less) - "we will never know what the stars are made of".
The man who uttered that was Pascal in 1833 or thereabouts. Ironically, it was at the same time that Fraunhofer was making his first solar observations.
Didn’t Auguste Comte say, in 1835, that we would never know anything about the chemical composition of stars in his Cours de Philosophie Positive?
...whereas we would never know how to study by any means their chemical composition, or their mineralogical structure, and, even more so, the nature of any organised beings that might live on their surface.
Jeff, recently bought a new Pentax VM 6x21 WP Monocular, initially as a pocketable instrument when out-walking for birdwatching, but with a fov of 8 degrees is good for scanning constellations etc. It will fit a pistol-grip and thence even a standard tripod. Rather similar to your 8x23. The main problem with opera-glasses was that they generally lacked independent eye-focus or variable pupil-distance. 'Small can be beautiful' .regards maf.
I’ll be interested to hear how you get on with that, Mike. Funnily enough, it had been on my mind to get something similar for when I’m out walking and cycling, or for a quick look at the Moon and planets, and prompted by this topic I ordered a relatively inexpensive one last night - 7x28. I’ll see how many of these lunar features I can spot using it.
I am a big fan of easy observing, and low maintenance equipment, as you know.
I have the Helios, Voyager, zoom 10X-25X42mm monocular. It's very good for general purpose and astronomy. It also functions as a microscope with its minimum focal distance of 25 inches. The Voyager can be attached to a grip or tripod.
It's good to see insects, especially butterflies, in intricate detail without being too close to disturb them. It retails at about £60.
