Science Siftings

New Zealand Tablet, 14 December 1911, Page 2555

Science Siftings

By * Volt.’

Work of the Honeybee. A writer in the Revue des Sciences Naturelles makes the following calculations in regard to the work done by the honeybee : When the weather is fine a worker can visit from forty to eighty flowers in six or ten trips and collect a grain of nectar. If it visits 200 or 400 flowers it will gather five grains. Under favorable circumstances it will take a fortnight to obtain fifteen grains. It would therefore take it several years to manufacture a pound of honey, which will fill about 3000 cells, A Gun that ‘ Fires ’ Cement. The cement gun is not a new weapon for the navy, but a machine for squirting concrete mortar in stucco form upon a surface of any kind. The apparatus consists of a compressor, with gasoline engine and two tanks, mounted on an automobile truck. One tank carries the dry mixture of cement and sand, and the other contains the water, and both are under pressure. A novel feature is that the dry cement mixture and the water are pumped separately to within an inch of the nozzle. At this point they are mixed, and so thoroughly that a very perfect combination is discharged upon any surface, rapidly building up a very solid concrete structure. Machine-made Lace. A machine has been invented in Lyons for manufacturing net and lace, the liquid material being poured on one side of a roller and the fabric being reeled off on the other side. One factory is now producing a thousand yards a day, and the process seems capable of indefinite extension and application to various sorts of woven knit and retriculated goods. The raw material is cotton waste and the finished fabric is a good substitute for silk. As in the process of making artificial silk the cellulose is dissolved in a puproammoniacal solution, but instead of being forced through minute openings to form threads, as in that process the paste is allowed to flow upon a revolving cylinder which is engraved with the pattern of the desired textile. A scraper removes the excess and the turning of the cylinder brings the paste in the engraved lines down into a bath which solidifies it. Tulle or net is now what is chiefly being turned out, but the engraved design may be as elaborate and artistic as desired, and various materials can be used. Since the threads wherever they cross are united, the fabric is naturally stronger than the ordinary. It is all of a piece and not composed of parts. Tall Trees. Tall stories and tall trees are in a sense closely related, but the Conservator of Forests in Victoria/ Mr. H. Mackey, seems to have thought it worth while to lay out.a few cold official facts on the question. ‘Where is the tallest tree in the world V He approaches his task in a ‘ hedging ’ manner by remarking that it is likely the tallest tree has not yet been discovered. Then, growing somewhat bolder, he declares- his belief that it is improbable that any exists of much greater altitude than some already measured. The chances, he says, are that there are scores of trees about 300 feet in height, and not one that reaches 350 feet. Mr. A. D. Hardy, an officer of the department, states that the greatest height actually ascertained by experts in Victoria was 326 feet 1 inch. This tree was of the eucalyptus amygdalina regnans species, and was found on a spur of Mount Baw Baw, in Gippsland, Its girth at six feet from the ground was 25 feet 7 inches. A tree of the same species discovered at Neerim, also in Gippsland, while only 227 feet high, had a girth of 55 feet 7 inches at 6 feet from the ground. Mr. Hardy quotes writers who refer to trees, as high as 480 feet having been found in Victoria, but the records were not authenticated. In referring to American forests, he mentions a redwood tree recorded as measuring 340 feet.