Having demonstrated that the Tudor telescope works with a magnification of about 3X the next questions to address are "how good is the telescope as an astronomical instrument and what could the Tudors have seen using it"? Opera glasses have a magnification of 3X and helpfully in 1890 Garrett P. Servis wrote a book entitled "Astronomy with an Opera Glass". The author found sufficient material to fill nearly 200 pages and since publication the book has never gone out of print. An archived copy can be found athttps://archive.org/details/astronomywithope00servuoft
For Garrett P. Servis, who lived in the northern hemisphere, the highlights of looking at the night sky through an opera glass were:
1. the Pleiades;
2. the Hyades;
3. the Andromeda Galaxy;
4. the moons of Jupiter (he could see two out of four); and
5. the craters and mountains of our own Moon.
Unfortunately the 3X magnification of Garrett P. Servis' opera glasses did not show much detail of Saturn and higher magnification is needed to show the planet's rings. Venus and Mercury where just white specks of light and Mars was an even smaller red speck. Even with my Konus 500 telescope at 100X magnification Mars appears no bigger than a small red lentil.
So my plan over the next few months will be to observe the above five features of the night sky using the Tudor telescope and if possible to photograph them and post them here.