Glyphs And Runes
You commence cleaning of the downstairs area.
The first floor, which I didn't really describe, consists of a foyer, with a sitting room off to the left, and a hallway off to the right. Down the hallway is a dining room, a kitchen, and servants' quarters, which you turn into your barracks. There is no food to be had, but you can find enough to eat in the jungle and in the ocean.
Your search of the kitchen reveals a dumbwaiter that goes up.
It is whatever time of day you wish it to be, depending on how long you take to clear the area thus far explored. When you first reach the sundial, it seems to be approximately 10 AM.
The telescope seems to be fixed in position at a series of glyphs carved into another cliff face across the jungle. It seems that there is a lake in the middle of this island, and the other cliff is on the other side of the lake. The glyphs seem to depict several geometrical objects, surrounded by what are presumably arcane runes. Hard to tell what's going on with them.
I'll assume you aren't breaking the base of the telescope, but if you want to, you can use it to better survey the area and the treetop house.