WEATHER RECORDING

Waikato Times, Volume 119, Issue 19886, 15 May 1936, Page 9

WEATHER RECORDING

LQLIPMENT AT RUAKURA. NEW INSTRUMENTS ADDED. AN [JP-TU—DATE OBSERVATORY. Additional equipment, including an anemometer for measuring the Velocity of winds and a sunshine recorder, have been installed at the meteorological station at the Ruakura Farm of in—struction. With these additfons the station will be made one of the most up-to—-date in the Auckland province. Equipped with modern instruments whose accuracy is tested periodically. and with emcient and experienced ofllcers. the recordings or the huakura Farm must be regarded as the standard for the district. for although town temperatures can be accepted as being accurate. modifying influences such as shade and shelter considerably affect them. "A Degree of Frost.” “Selentiflcally there is no such thing as a. degree of frost." stated an otllcer at the farm. lie added that a point at which normal vegetation would be affected was 30.3: degrees (Fahrenheit). and this was the basis from which the intensity of frosts was recorded, each degree below this being commonly regarded as one de—gree o! frost. It was explained that while the maximum and minimum temperatures might be recorded on special thermometers, the duration of a high or a low registration might not be shown. Accordingly many people were prone to misjudge reports given. For instance, last Saturday 12 degrees of frost were recorded. while on Tuesday ihe reading was only 2.2 degrees. Yet the weather seemed more intensely cold. the absence oi sunlight accentunting the etYect by actually prolonging the duration or low temperature. Mis—conceptions ot the intensity of frosts frequently occurred through other influences not being considered. obtaining Temperatures. In explanation of the method by which the temperatures were obtained it was pointed out that a standard frame for thermometers was employed. adding to the uniformity of readings taken throughout the world. Of particular interest among the instruments is the sunshine recorder. This consists of a solid glass sphere measuring about 3 inches. which has the street or magnifying the heat of the sun‘s rays, and of concentrating them on-a narrow band or sensitised paper which becomes charred when the sun in shining. Passing clouds obscuring the sun make a. break in this tine. Should the day remain cloudy throughout the line of paper will remain intact.

The anemometer. too. is Interesting. the number of turns per hour of a revolving cup—shaped apparatus being recorded. The velocity of the wind may be calculated by the number of revolutions per hour.