there she is the rube goldberg door opener sure sure i know they have a gadget called an electric guy that does practically the same thing but that's no good for a waiter you see if you like the electricity you might give the waiter a shock then he'd forget to come back to pick up a step and he lowers his professional standing on his door offer up a really work it's very simple but watch close now here's what well folks i suppose that i want to among you think that my inventions are a bit ahead of that time and shade fantastic perhaps all right go on and say it's downright screwy but let me tell you something i've got lots of company genuine invent it guys who've got their stuff protected by the united states patent office and believe me some of it needs protection if you know what i mean for instance now here's an invention that was granted patent number five five six two four or eight back in the year eight hundred ninety six but don't ask me why this little nifty is a labor saving devices if there ever was one it's an automatic had temper for the lazy low theriault fits snugly inside of this still looks dirty that is in addition to the wear a slightly addled whenever a young heiress passes by well anyway this is just one example of the many queer devices that have actually been patented and here's a copy of the patent the pro oh there are literally hundreds of such patents on file in the united states patent office the inventors were all perfectly serious they really believed that their inventions would make things easier for us and our lives pleasanter and safer but by far the most persistent dream of inventors has been to get something for nothing that is to create a machine that was started self overcome all fractions and still have enough power left to do useful work and short perpetual  motion machines now here's a typical it sample of what i mean the famous old standby of course you all know that when something is dipped under water it seems to lose weight so this particular perpetual motion machine is designed to have some of the weights in water and some of them out of water at all times it's all very simple and so are you if you think it'll work like confidentially i've got one that will work and if you'll excuse me for a few minutes i'll show you no mr goldberg not even your genius is equal to that task in fact the united states patent office will no longer grant a patent for the design of a perpetual motion machine because the experts in that office know that you can't get something for nothing that you can't get power out of an engine without paying for it in fuel fortunate for us however man has discovered a virtually unlimited source of power he has paid for that power by years of painstaking research and experimentation that source of power is gasoline the chief product of the petroleum industry gasoline in fact is the greatest single source of power in the world today and the automobile engine is by far the greatest user of gasoline power here's a device that looks like a cross between a trench mortar and an automobile engine it's just a thing to illustrate the principles of getting power from gasoline liquid gasoline contains the power all right but unaided it can't release the force  holds when a light is applied to it liquid gasoline burns as innocently as a wax candle this proves what we all know gasoline has to be mixed with plenty of air to release its power then gasoline has more force then an equal amount of gunpowder into the first cylinder goes on mixture of air and gasoline into the fourth cell and there are an equal weight of gunpowder when the cylinders are touched off with an electric spark or the swoosh shows lots of power gunpowder has the better of it here but the gasoline hasn't taken off its rents gasoline does its best work when it's under pressure in the cylinder fueled with a mixture of air and gasoline the piston is pressed down until the mixture is under high pressure it's clear that the highest pressure to the testimony develops more power one method of obtaining this added pressure in the automobile engine runs to increase the piston stroke but when carried beyond a certain point the engine starts to knock so several other changes were made to increase power without causing a knock first the piston top was redesigned so that it will mix the air and the gasoline together more completely in the latest engines the roof of the combustion chamber around the end take valve has been lowered just a fraction of an inch but that was enough so that now the gasoline is mixed with free air and compressed more from more power today the driver of the motor car doesn't get something for nothing but he does get more power than ever before  gasoline he buys our available supply is a fuel now do more work with increasing efficiency and economy