Misc: U S captials Washington?

Questions

What is the trade name for the strong woven synthetic material used for hulls and sails, radial tyres and bullet proof vests?

What did Alexander Graham Bell invent in 1881 to help doctors caring for Pres James Garfield agfter he was shot?

Which american blacksmith invented the steel plough in 1837?

What was stored in a Leyden Jar?

Between 1620 and 1624 Cornelius Drebbel built and tested the first what on the Thames?