LET me offer you this morning a conception of the kind Jonathan Swift referred to when he spoke of "scattered notions likely to be of singular use for the common people, as furnishing excellent materials to keep children quiet when they grow peevish, and providing topics of amusement con a tedious winter's night".
The project falls into the "Things to Make and Do on a Rainy Day" category - the manufacture of a barometer to measure the atmospheric pressure in your garden.
Take two circular wooden discs, as Mrs Beeton might have put it, and combine the with a sheet of paper and a modicum of glue to assemble a hollow airtight cylinder. The discs should be about 3 in in diameter with a thickness of a quarter of an inch.
The paper, about 18 ins long, is rolled to form the curved surface of the cylinder, and the discs provide the two ends. Repeat to make a replica, and you should now have two objects which look like elongated cans of beans - unopened, hollow, and of course, devoid of beans.
Next take a wooden dowel, 20 in long and glue a cylinder, end on, to each extremity. Now you have a kind of dumb bell, which is mounted out of doors atop a post in such a way that it is horizontal, pivoted at the central point, and can "see saw"
freely in the vertical. Voila, our DIY barometer, The designer of this precision instrument has left us with exact instructions as to how to use it: "Only one thing is needed now to make our barometer point to changes in the weather.
"We bore a hole with a good sized gimlet in one of the wooden ends of one of the cylinders. This establishes communication between the outside air and the air inside that cylinder; meanwhile the other cylinder contains only the air that was originally enclosed within it, and which is isolated from the outside air.
"Now, if the outside air is heavier than that in the closed cylinder, the closed cylinder will rise, and this tells us that the weather will be fine.
"If on the other hand the surrounding air is lighter than that in the closed cylinder, the cylinder that has the hole will rise - and this tells us that bad weather is on the way."
The ideal is that in the latter case the pressure must be falling, and this, as we know, suggests that the weather may become more changeable. It would be unwise to depend on the apparatus for a forecast, but it would be interesting to see if, properly constructed, it really did react to changes in atmospheric pressure.