The Saturday Science Half-Bakery

There are quite a few of the many projects, experiments and demonstrations that I have tried that for one reason or another haven’t quite been finished. Some did’n’t work, but showed promise. Others have half-worked but need modification to work properly, while some I simply haven’t gotten around to finishing.

If you fancy trying something that I – and maybe no one else – has fully tried – then one of the projects below might be for you. Maybe with your input some of these half-baked rojects will make great cakes or pastries !

Electric-current-enhanced-friction funicular railway

How can you go up a steep hill with a railway ? If a hill is really steep, then the coefficient of friction between train and track may well be insufficient to guarantee grip. The train will then slip, and, if the hill is too steep, you simply can’t go up it with a standard type of steel wheel on steel rail type of railway. You could try hauling the train up with cables and winches. You could try a ‘rack-and-pinion railway, with a gear-tooth rack on the track and with gear-wheel ‘pinions’ on the engine. But what about simply increasing the coefficient of friction between the steel wheel and the steel rail ? You could apply a friction-enhancing material to the wheel and rail, such as rosin, the resinous tree-sap from pine and similar trees, used by ballet dancers on their shoes and violinist on their bows, although coating surfaces with rosin in a consistent way is tricky. But you don’t need to go to the trouble of doing this. Remarkably, however, friction can be enhanced with electricity. Here is how…

More coming soon…

Wells-turbine zero-angle-of-attack fan

You might think that a set of propeller blades with a zero angle of attackwould not do anything useful. But, remarkably, they can. Believe it not, the system has been used in turbines for generating power from to and fro air flow in an extraordinary system for generating power from waves in the sea. The really clever bit about this system, the Wells turbine, is that the ‘fan’ keeps turning the same way all the time, even though the air is reversing.

You can make your very own Wells turbine in a simple way using a traffic cone, a disc of zero-angle turbine blades and a small electric motor as a dynamo. Look up ‘The Impossible Turbine’, page 477 onwards in my book The Ultimate Book of Saturday Science and you can see how to make systems like this. But if a turbine can be made to generate electricity with an air flow with crazy zero-angle turbine blades, what about a fan, a compressor, generating air flow from electricity ?

Can it be done ? More coming soon…


Alan Wells, for the Secretary of State for Energy of Her Britannic Majesty’s Government, Wave Power Apparatus, US Patent 5,191,225 (1990)

U-tube liquid piston pump

A piston pump is a very familiar concept. A cylinder-shaped piston is a tight fit and goes up and down inside a hollow cylinder, pushing gas or liquid to and fro, and, with the aid of valves, from inlet to outlet. Less familiar is the idea of using a piston of liquid inside a hollow cylinder. No less a person than Albert Einstein thought that this was a neat idea and came up with a refrigerator design which used a liquid metal (also a neat idea) as the piston going up and down inside a solid metal hollow cylinder to pump the refrigerant gas around the fridge circuit. The idea really worked, and quite a few fridges were made using the idea. Einstein moved the liquid using another neat idea, using a magnetic field to move the metal. This works, but it is rather tricky. Here we look at simply moving one side of a U-tube up and down to move the liquid up and down, and move the liquid on the other side of the U-tube up and down.

More coming soon…

Streaming Potential generator