Concrete Supplies

Grinding concrete requires skill and practice to avoid making the surface further damaged. It also requires the right tools and supplies. With careful use, these tools remove the stained or damaged surface of a poured concrete slab. Finishing creates a smooth, shiny surface that makes an ugly concrete patio or floor attractive again.

How to Design a Newtonian Telescope

In a Newtonian telescope, the image enters an open end of the tube, travels the length, bounces off a curved mirror, travels back up toward the open end, bounces off a secondary mirror at 90 degrees and travels through a focuser and eyepiece. All you need to plan the design is the specifications of your telescope optics. After that, it’s simply a matter of taking measurements and placing the optics in the right configuration.