XXX. 



METEOROLOGICAL OBSERVATIONS TAKEN AT THROCKING, 



HERTS, DURING THE YEAR 1880. 



By the Rev. C. W. Hauvet, M.A., F.M.S. 



Bead at Hertford, 22>id March, 1881. 



The position of Throcking is about Lat. 5 1° 57' N. ; Long. 0° 3' W., 

 and the district is drained by the River Rib. My observatory 

 is 484 feet above mean sea-level, and it contains the following 

 instruments, all by jS'egretti and Zambra : — a Fitzroy storm- 

 barometer ; a dry- and wet-bulb, a maximum, and a minimum 

 thermometer, the thermometers being inclosed in a Stevenson's 

 screen, with the bulbs about 4 feet from the ground ; a solar- 

 radiation and terrestrial-radiation thermometer, the former fixed 

 4 feet, the latter 6 inches, from the ground, both being well exposed. 

 All the above thermometers were verified at Kew Observatory in 

 December, 1879, and all observations have been corrected for index 

 errors, and the barometer-values have been reduced to 32° and sea- 

 level. A rain-gauge of the Snowdon pattern, having a diameter 

 of 5 inches, and with its receiA^ng rim one foot above the surface of 

 the ground, completes my set of instruments. My times for observing 

 are 9 a.m. and 9 p.m., the self-registering thermometers being 

 read and the gauge emptied onl// at 9 a.m., and the maximum 

 readings and the amount of rain being entered to the previous day. 

 The mean temperature is the mean of the max., the min., the 9 a.m., 

 and the 9 p.m. readings of the thermometers. In the accompanying 

 tables (pp. 234, 235) I give the result of my observations ; all the 

 values being derived from the 9 a.m. observations only, excepting 

 the mean temperature. 



Gexeeal Remarks. — There is little about the weather of 1880 

 that is in any real sense abnormal. As regards temperature, al- 

 though below the mean throughout the year, owing no doubt to the 

 great absence of sunshine, we have had no such excess of cold as that 

 of Dec. 1879 or Jan. 1881 ; and certainly, as will be seen presently 

 there has been no excess of heat ; again as regards rainfall we have 

 had no such heaA-y fall as that of Aug. 2nd and 3rd, 1879. Tem- 

 perature was below the mean during the whole year, the deficiency 

 being most observable in Jan. and Oct., least so in Feb. and Mar. 

 Still there are some particulars which I think call for notice. We 

 have experienced three deep barometer depressions, one in February, 

 one in October, and one in IS'ovember ; whilst in January and De- 

 cember the mercury attained a very high point. In February the 

 lowest point noticed was at 8 a.m. on the 17th, when the mercury 

 stood at 28-84 ins. at sea-level. Between Oct. 25th and 30th there 

 was a depression amounting to 1-36 in. and a recovery amounting 

 to 1-30 in., the max. and min. pressure being, 25th 30-19 ins. ; 28th 

 28-83 ins. ; 30th 30-13 ins. On Nov. 18th pressure was 28-83 ins. ; 

 19th 29 80 ins. ; and by the 21st the mercury had reached 30-46 

 ins. Thus the recovery was 1-63 in. between the 18th and 21st. 



VOL. I. — PART VII. 16 



