Which digital protractor is the best?Protractors, both manual and digital, are used to measure various angles. You might find yourself needing one for a DIY home project or if you’re building ...

There is space in the interior of the rectangle—and on both sides—for other scales. Early rectangular protractors were often made of metals such as brass, but in the 19th century, makers manufactured ...

Old school vernier calipers served engineers and machinists well for a long time — and did a perfectly good job. Digital models then came along and were easier to read. They now rule the roos… ...

The protractor is stored in a black and red leather and cardboard case that is badly worn. William Young McAllister (1812–1896) was a third-generation optician and dealer of mathematical instruments ...