Science Siftings

New Zealand Tablet, 17 August 1911, Page 1603

Science Siftings

By ‘ Volt.’

Wood-Reinforced Concrete.

An English engineer has suggested a novel type of reinforced concrete, in which wooden beans and laths take the place of iron rods and wires. The new material, which its inventor calls ligno-concrete, is intended as a substitute, not for ferro-concrete in general, but chiefly for wood as employed in the construction of roofs, footways, posts, etc. The wooden parts act as traction members, and the concrete as a compression member. ' It has been demonstrated by many tests that ligno-concrete is as strong as ferro-concrete, when the wooden beams of the former have a cross-section which makes them as strong as the steel bars of the latter. The tractile strength of steel is eight or nine times that of wood, but steel is ten to fifteen times as costly as timber. Hence ligno-con-crete, if it proves durable, may advantageously be substituted for ferro-concrete in many cases. The question of durability can be decided only by time and experience, but the many known instances of the permanence of wood protected by cement indicate that the decision will be favorable.

The Dodo.

We are all familiar with the phrase ' as extinct as the dodo,' and there are uninformed.folk who believe that it was as fabulous as the phoenix. Certain it is that it became extinct almost as soon as it became known. It was found in the island of Mauritius by the earlier explorers, first the Portuguese and then the Dutch. The bird—which resembled in appearance an unfledged duckling—was unwieldy and incapable of flying, and it was too fat for its little wings to lift it from the ground. It was knocked on the head by the sailors and worried by the pigs they introduced, and so was soon exterminated. About the beginning of the seventeenth century, between 1610 and 1620 specimens were brought alive to Europe, and were exhibited as a show. Oxford once possessed a stuffed specimen at the Ashmolean Museum, but as it became mouldy and eaten by insects, it was destroyed. The curator cut off its head and one foot and kept them. The head and foot, together with another foot in London, and skull in Copenhagen, are about all we have left of dodos seen in a living state by Europeans. Another bird, the great auk, came to an end only about sixty years ago. It used to be observed on the rocky islands of Scotland, Iceland, and Greenland, but now it is 'as extinct as the dodo.'

How to Float an Invention.

Some years ago an American promoter went to Berlin to sell the patent rights of a new bottle-making machine which made 20,000 bottles a day, replaced hand labour, and lowered cost of production. He found the German bottle manufacturers all bound up in a verein.' They considered the state of the bottle trade very good, liked their present methods of manufacture, and did not respond at all to the suggestion of this new Yankee machine being worth a million and a-half marks to them. Instead of going back home after this rebuff (says the World's Work), the American visited one of the largest mineral-water companies in Germany and asked how many bottles they bought yearly. They told him a matter of millions. Then he asked how much they were paying for bottles, and when they gave the price, offered to install in their own plant a machine which would turn out all they could possibly use at less than half their present cost. The offer was accepted, and when the machine began work the mineral-water people were delighted. The loss of this important customer brought the bottle manufacturers around in a hurry. • They bought the German rights, and that machine is being built and used to-day in Germany,