Thermometer Screen Research Articles

Ozone at Sea

DURING my voyage hither from London in the Maranoa, viâ the Canal, and calling at Malta, Aden, and Colombo, I was surprised at the low values for ozone as registered by Moffat's tests, which I pinned to the “uprights” in Stevenson's thermometer screen. I tried periods of exposure varying from half an hour to twenty-four hours, and the highest value noted was but 5.6 for eight hours (scale 0 to 10). The test papers, however, were always tinted, more or less, sometimes to 3.0 in half an hour, whereas tests exposed at the same time and examined when eight hours had elapsed, only gave 4.6. At Ben Nevis and Fort William, and in the moorlands of Staffordshire I have recorded far higher ozone values than at sea under the same force of wind and like periods of exposure. From my long experience of these tests I cannot consider them satisfactory; but in the absence of a more reliable method I would strongly suggest that they would give results more intercomparable if uniformly exposed for an agreed hourly period, especially at the various land stations.

IV. Note on the establishment and first results of simultaneous thermometric and hygrometric observations at heights of 4 and 170 feet, and of siemens’ electrical thermometer at 260 feet above the ground

It is just a century since James Six (the inventor of the well known Six’s registering thermometer) commenced some occasional comparisons of the temperature of the air at the top and bottom of the tower of Canterbury Cathedral. We do not precisely know the position in which the instruments were placed, and, as thermometer screens had not then been invented, his observations can only be accepted as approximately correct; but as the work in which they are recorded is rather scarce, it may be well to give an analysis of the results.

Ben Nevis Observatory

IN NATURE, vol. xxvii. p. 39, I gave a brief notice that on November 1—owing to stress of weather forbidding the regular daily ascents of Ben Nevis—I was obliged to discontinue the daily work of the meteorological observing system on the summit and slopes of the mountain. This was in simultaneous connection with my system of observations near the sea-level at Achintore, Fort William. As in the previous summer, I had the honour to organise and carry on the work under the auspices of the Scottish Meteorological Society. The experience gained in 1881, when I first commenced observing on the Ben, enabled me to draw up and submit to the Society a more elaborate plan of mountain observation for the summer and autumn of 1882; and as I have been fortunate enough to carry it through for five months without any hitch, and as I am not aware that anything of the kind had, previous to my first undertaking, been attempted, I am naturally anxious that NATURE should have a more complete account of my last year's operations. My plan was to have fixed stations at different altitudes between the main observatories at the base and on the summit of the mountain so placed in fact that I could observe regularly at half-hourly intervals during the daily ascent and descent of the Ben; to extend the number of summit observations to five sets; and to have in every case simultaneous observations taken at the sea-level station—my grand base of operations. All this was with a view to localising disturbances existing in the stratum of atmosphere between the sea-level and the top of Ben Nevis, to furthering meteorological research generally, and so ultimately to gain forecasting material. I arrived at Fort William from Edinburgh on May 25, and at once proceeded to give effect to my plans. During the next few days I was engaged mainly in erecting Stevenson's thermometer screens, and laying out the sea-level station; in establishing a new “midway” observatory at the lake, erecting screen, and building there a granite cairn for a barometer; and in reopening the temporary observatory on the summit of the mountain. It was only by dint of great exertion and a gang of men that I got all in order on the top of the Ben on May 31. I had no occasion, however, to alter the arrangements of the previous summer; and the heavy work of reopening chiefly consisted in digging out from the vast accumulations of snow the barometer cairn, hut, and thermometer cage which here, as a safeguard, incloses Stevenson's screen. The snow, in fact, was nearly four feet deep, and it was necessary to cut out wide areas around the instruments. I also erected another screen to contain Negretti and Zambra's self-registering clock-hygrometer, most kindly placed at my disposal by that eminent firm for the purpose of obtaining 9 p.m. values. I had also to fix a new roof of ship's canvas to the rude shanty that affords some little shelter from the piercing cold and storms. The barometer, a fine Fortin, had been left in its cairn built up during the past winter; and great labour was expended before the north side of the cairn was reopened, the stones being so hard frozen that a crowbar had to be employed. The instrument was found in good condition.

On the effect of different kinds of thermometer screens, and of different exposures, in estimating the diurnal range of temperature at the royal observatory, cape of good hope

On the effect of different kinds of thermometer screens, and of different exposures, in estimating the diurnal range of temperature at the royal observatory, cape of good hope