For a couple of minutes of paper or paperboard will be able to make strenuously device that will instantly show you the centre of any circle, for example, the base of the cylinder. The secret lies in the fact that the rays arrows, encircling a circle located at an angle of 90° to each other, and a “shaft” of the arrow divides this angle in half, and it always passes through the center.
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CASE FOR SOLDERING IRON
...can be made from scrap pipe of appropriate diameter. The case will protect the working part of the tool during storage. S. CHIRIKOV, Tallinn
TRUCK-DUMP TRUCK
To make this easy and convenient truck — an assistant gardener and grower — only need that, and so there are in any country or agriculture. But serve it on any auxiliary works:...
