The lens telescope, or refractor, was vastly improved when it became possible to manufacture high-quality lenses made from flint glass.
I remember as a child seeing them through my small backyard refractor and it was unmistakable.
A three-inch refractor will give an excellent view.
domeless solar refractor
A three-inch refractor will give an excellent view as well as showing Titan.
He began examining nearby galaxies with a 10-inch refractor to see whether any stars had flared up.
The preconditioned fastest descent means in inversion achieves simultaneous in - versions of overlying-bed velocity and refractor depth.