BRAIN TEASERS
Brain Teasers User Profile

Srdjan Cvetanovic

rank
600
points
0
See full ranking list
short ranking list
598. Crystal Goodnight 0
599. Ethelena Maheia 0
600. Srdjan Cvetanovic 0
601. Usman Qamar 0
602. Binod Singh 0
last 3 solved tasks

Screw machine

In 1798, the first U.S. patent for a nut and bolt machine was issued to inventor David Wilkinson of Rhode Island. His machine for cutting screw threads incorporated a slide-rest, with a heavy carriage supported on three rollers Afterwards, his machine was operated by water power at Pawtucket Falls, RI. Wilson was a machinist who also produced iron forgings and castings for the cotton industry industry there, such as Slater's Mill. Wilkinson later produced a large general purpose lathe (1806), a pioneering advance that founded the American machine tool industry. [The first machine of importance for trimming the heads of nuts and bolts was invented later by Micah Rugg, who was issued U.S. patent No. 2,766 on 31 Aug 1842.]«

Double negative

A linguistics professor was lecturing to his class one day. "In English," he said, "a double negative forms a positive. In some languages though, such as Russian, a double negative is still a negative."

"However," he pointed out, "there is no language wherein a double positive can form a negative."

A voice from the back of the room piped up, "Yeah. Right."

Jokes of the day - Daily updated jokes. New jokes every day.
Follow Brain Teasers on social networks
This site uses cookies to store information on your computer. Some are essential to help the site properly. Others give us insight into how the site is used and help us to optimize the user experience. See our privacy policy.