Very strong shatterproof plexiglass
Protective glass surrounding the boards first appeared in the NHL at Toronto's Maple Leaf Gardens in 1948. The use of protective glass in all NHL buildings became mandatory in the 1950s.
you use the same glass as you use for winter horticultural, standard, or laminated glass.
There are many kinds of scaffold boards to use in a desert climate the best one for desert climate will be Climb-Pro 345840 Scaffold Boards. I also think Planks Bakers Scaffold boards and PRO-SERIES scaffild boards.
They use optics
No, Bantu are the old tribes in Africa. However, the commonly use "voodoo" type practices. They use wiji (We Je) boards, which are boards they rub to "speak with the dead."
White boards use Dry Erase Markers. Black boards use Chalk.
Convex lense
Circuit boards are not dangerous to use and they are not some type of skateboard. There are tons of varieties of circuit boards for different things you are trying to control. You'd need to ask a more specific answer since there are so many types.
NO
Any type of clean cup or glass will do. But if you are setting a table properly a water glass or tumbler should be used. This is a medium sized glass with a broad flat base and straight sides.
same eraser both on white boards and chalk boards?
You need a diamond tipped drill bit to drill glass or tile.