Plans on How to build a shower?
The wheel, it's one of the most ancient important inventions. The Zero, it even became more important today with the development of information technology.
Benjamin Franklin's lightening rod. I can look out my back window and see one still in use. Also, bricks, anchors, maps, thermometers and tumbler locks.
Probably the most common old invention still in use today is the wheel. Just imagine where we would be without wheels!
If you look, the all out racers run 1 piece suits, sure you can zip a two piece together, but that is only 8 across the back, so what about you stomach area? Add in the factor of cost, a 1 piece is a fair amount more than a 2. Looking at the cost factor, and the seasonal weather, I went 2 piece, spring and fall I have my jacket w/ the liner and a pair of overpants, not chaps, and when summer hits it's peak then it's just the jacket with the liner out. Another question for you is what kind of racing do you plan on doing? Almost all the tracks require a leather jacket, textiles won't make it, depending on the speed, then the requirements grow. You might want to check into the requirements of the track to what you want to do before making a total commitment.
A lightning rod is a pole on a building with an 'earth' wire which attracts the electricity down it to ground harmlessly instead of expending at the roof top (blowing it off, setting fire to building, killing occupants, etc). Ben Franklin is said to have invented it and proved lightning and the new stuff, 'electricity', were the same thing - late 1700s. As others have said - bow and arrow, paper, pottery/houseware (not the microwave, of course), basic fishing gear, hand-held weapons, early firearms/gunpowder, heaps of things. The Archimedes Screw' is a type of pump used to raise water from rivers or pools. It is still used around the world, although powered by engines not animals or people in the West. It was invented before 200BC (can't remember date, might be about 300BC) and is probably installed along levees in USA where floods are common to pump water back into rivers, etc, when flood threatens. As to the two most important 'old' inventions: Fire - or at least controlled fire for heating and cooking (and maybe in warfare, too, with fire arrows and the like). [Pre-history!] Wheel!! Machinery depends on wheels, normal or cog-wheeled, just about everything else does, including transport, of course. And, as you mentioned mousetrap, Archimeded played a role there, BTW. Although 'levers' like the crowbar were known before him (the Pyramids would not have been possible without them and the roller - a type of wheel variation), he was the one that worked out the principle behind how they worked. [Like BF and lightning, which had been around long before Mankind.] The traditional spring mousetrap relies on combining the turn of a round bit ['wheel'] with the force of closure based on the force/distance calculations of a leverage formula. (Not that the inventor of the original one would have ever thought about it in terms of force/distance/mass/etc.)
