SUN AND RAIN.

Auckland Star, Volume LXVIII, Issue 158, 6 July 1937, Page 5

SUN AND RAIN.

EYES ON WEATHER.

PUTTING IT IN FIGURES.

OBSERVER'S DAILY WORK To you—unless it ie your hobby or your business —frost is just so much whiteness and so much cold, rain just so much puddles and mud and dampness, sunshine just so much of a surprising change. You measure the weather in sensations alone, not in statistics and technicalities. Xot so Mr. S. M. Yallop, for it is his business. He is the Government observer in Auckland and holds the key to that circular, ironbarred enclosure in Albert Park, with its spinning metal cups, its gleaming sphere of glass, its white-shuttered box. Analysing the weather, resolving it into figures and positive definitions— that's the daily job of Mr. Yallop. Each morning at nine o'clock, standard time, which means 9.30 "clock" time during the daylight-saving period, he enters the enclosure, opens the white box, climbs the ladder to the top of the conspicuous pole. Up there the hollow metal hemispheres of the anemometer, as it is known, rotate in what wind there is, ticking it off and recording it in miles. It gives not the actual rate, but the number of "miles of wind" from 9 a.m. to 9 a.m. Measuring the Sunshine. Up there, too, is a four-inch glass sphere that gleams in the sunlight, catches the eye of one of the countless visitors who peer through the bars into this sacred circle of ground, and stimulates his wonder. Here is the explanation: It is part of an ingenious arrangement which records for Mr. Yallop the 24 hours' quota of bright sunshine. It registers permanently with a charred line on a special kind of cardboard; often the line is a series of dots and daeh.es—like an enlarged Hanse «ode

transcription—telling him the sunshine has been fitful and broken by clouds; sometimes there is no mark at all, and that means no sunshine at all. The glass ball sharpens the sun's rays into a point which burns its way over the sensitive card, marked in hours and so treated that it is not affected by moisture. Down below is a copper vessel and a funnel which collects rain water, measured by Mr. Yallop with a special minutely-graduated glass. Thermometers stand in the white box; there are wet and dry bulb instruments which by a! principle of water evaporation give the I amount of humidity in the atmosphere. Then there is the maximum thermometer, containing a mercury column which rises to the highest temperature during the day. Reaching that point, it is prevented from receding as the temperature decreases by a constriction in the tube— but a shake sets it right for the next period's reading. Another thermometer similarly gives the minimum temperature. It has a needle floating in a spirit column, and carried by surface tension to the lowest temperature point, it stays there. Plotting Weather Map. Two ground thermometers, one 3ft and the other lft down, ere placed in iron castings sunk into the ground. The [deeper records from approximately 53 degrees at the coldest time of the year to about 07 degrees at the warmest time. It rises and falls gradually throughout the year, being hardly affected at all by the outside temperatures, while the shallower one is easily so affected. Frost is registered on another minimum thermometer placed 2Jin above the grass, and there is a solar thermometer, its bulb in an evacuated glass casing and unaffected by cooling winds, which gives the actual heat of the sun's rays. The bulb is black to absorb the heat* Then there is the barometer to be read in the science block of the University College, where Mr. Yallop has his headquarters. He records his observations and wires them to the meteorological office in Wellington. From otiipobservers stationed throughout the land, from post offices and ships at sea, similar data comes in to Wellington to be plotted on the weather map as a basis for the day's forecast.

And there Is sought the answer to the burning question: What will the .weather do next!