Science Siftings

New Zealand Tablet, 4 November 1909, Page 1755

Science Siftings

BY • VOLT

IA Cheap Aeroplane. - The Paris Journal of September 14 says': M. Santos Dumont, on his small monoplane, yesterday flew at St. Cyr, and, crossing the valley between that place and Due, landed near the marshes, having covered five miles over . the fields and trees in five, minutes. He thus won two wagers, one against Mr. Farman, who had declared it to be impossible to make a long-distance . flight with a machine of such small dimensions as M. Santos Dumont's Maiden, as it is called. >The Maiden has a speed of sixty miles an hour. After the flight,' M. Santos Dumont announced that, with a desire to promote aerial locomotion, he was making the patents of his aeroplane public property,, so' that anyone' could get the plans of themachine from him and build a similar one. The machine, including the motor, costs less than £200. On Dangerous Ground. Much anxiety (writes the Auckland correspondent of the jOtago Daily Times) has been caused to Dean Lightheart by the ravages wrought -by thermal action on the church at "Whakarewarewa. The building was erected by Father Kreymborg, and" -the • excavations had' formed numerous steam vents underneath the structure, with the I result that as time went, by the timbers were affected to I such an extent that "tlie ! - church was in danger of collapI sing. Fortunately, owing to the skill of Father Wientjes, I this has been abated. Father Wientjes has constructed I underneath the church a number of concrete conduits, I one extending almost" the length of the building. These I conduits tap the principal steam vents and conduct " the I steam to the rear of the building, where it escapes in a I huge volume. The work was ojf a difficult and tedious I nature. Should the concrete stand the test of ttie thermal ■ action the safety of the. church is assured. I A New TJse for Concrete. I Concrete has rapidly grown into favor in recent years las a building material, but few people are aware that it lhas been used for building boats. According to a writer ■in Cassier's Magazine, however, the idea of building a Iconcrete boat is not a new one. Lambot, in 1850, built a Iboat of this material. About eleven years ago Mr. D. B. ■Banks built a two-masted schooner, 65 feet in length and 116 feet beam, and drawing 14 feet of water, of concrete, (reinforced by multitudes of -small steel rods. This craft lis said to be quite swift in heavy weather, although someBwhat slow in light breezes. The Gretchen sails in salt (water, having been as far north as the vicinity of Hudson's ■Bay, and as far soxith as Cape Hatteras, if not further. IShe was once driven on the rocks at Cape Charles, but Bescaped without damage. About two years ago the Sig■nori Gabellini, of Rome, built a reinforced concrete barge ■for salt water use in the neighboring waters. This vessel Ks of 150 tons' burden, and is said to have been quite Successful. ■ How to Drive a Nail. I One who thinks that the driving of a nail simply conftists in getting the whole length of it out of sight, has ■ittle conception of the real nature of the operation. A Kiail driven by an expert will often hold several times as Hnuch as one ill-driven ; while, too, it is often made to Kraw the parts into place. If you have ever watched a Mnecnanic driving nails, you have doubtless noted that he H-arely drives one at right angles with the face of the Hvork. There is a reason for this. Suppose that he is Miailing the weather boards on the frame of a building, and Hlesires to draw the board down tightly against the one Htelow it; he points the nail downward, and a few .wellMo nsidered blows at the last produce the desired effect. .If board is bent edgewise, so that much force is required, he will start the nail in the upper edge, pointing W^ery sharply downward. Again, two nails driven in a at different angles will hold it in place much more than the same nails would if they were driven at Hight angles with the face of the board. Did, »you ever that, in driving a nail in very hard wood, one man« do it successfully, /while another succeeds only in the nail up" before the point has fairly entered wood? The difference lies" in the fact that the expert the nail fairly, and not too hard, 'coaxing' it in; the .other" strikes too hard and with indirection." may be probably mentioned, right here, that in driving nail into very hard wood, it is usually profitable to dip end in oil or grease. This will not sensibly interfere the holding qualities of the nail, while it will be to very materially facilitate -its driving.

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