British Rainfall 1912, p.56
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'Seathwaite' Pattern Rain Gauge British Rainfall 1912, p.56 THE "SEATHWAITE" PATTERN RAIN GAUGE In order to meet the peculiar difficulties of measuring the rainfall in very wet and exposed positions where the gauges cannot be visited frequently, an attempt was made last year to devise a form of instrument which would be free from the most objectionable features of existing rain gauges. To meet the difficulty of collecting the whole rainfall for a month in a very wet position the rim of the funnel was made with a diameter of five inches, while the containing vessel had a diameter of eight inches. Hitherto, gauges in which the funnel was of smaller diameter than the receiver were open to the objection of horizontal joints, the soldering of which is particularly liable to give way and to allow rain to enter. This difficulty has been overcome by attaching the five-inch brass ring to a long and gently sloping cone rolled out of one sheet of metal, so that it has only one joint. Within this cone the funnel is fitted, its diameter being naturally greater than five inches, and the lower end of the cone is fitted over the eight-inch receiving vessel, the sides of the cone projecting beyond the receiver and coming down to within half an inch of the ground whene the cone is in place. The cone is attached to the cylinder by means of a separate device in the form of a bayonet joint, which, when closed, cannot be opened until an extremely inconspicuous brass catch has been pressed back. It is hoped that this device will make the gauge less liable to be tampered with, as anyone ignorant of the construction would have great difficulty in discovering how to remove the cone. The difficulty presented by the freezing of the contents in winter or of evaporation of the water in summer, from a gauge which is left for a month between visits, has been attacked by making the receiver a cylindrical metal can, fitting loosely inside the outer case, which is constructed with double walls and double bottom, the intervening space being packed with a non-conducting material, rendered waterproof and sealed from contact with the air. This makes the outer cylinder large and heavy, and when it has been buried to the proper |
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weather station, Seathwaite | ||
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