98 



the means for each month are certainly very near the truth, the artificial cooling 

 and heating just mentioned appearing to balance each other very perfectly. 



On the 27th of June, at 2 p.m., a very extraordinary difference between 

 the dry and wet bulbs was recorded, viz., 17 degrees. The degree of humidity 

 on this day amounted to 42 '8 only, the aii' being di'ier then than at any other 

 period during the whole year. 



Whilst upon the subject of thermometers I may do well by giving a hint to 

 those who are about to commence observations with these mstruments, respecting 

 the great importance of placing thom properly. In no case should thermometers 

 be attached to the walls of buildings. Properly constructed stands should 

 be used ; that contrived by llr. Glaisher being, I believe, the best. The 

 thermometers should be protected from rain, but exposed freely to the action 

 of the air ; the open side of the stand should face north, and there should be, at 

 least, a clear space of 50 feet in length in front, precautions being taken to 

 protect the instruments from the rays of the morning and evening sun during 

 the summer. The thermometers should be suspended four feet from the ground. 



The rainfall at Hereford during 1867 was about 1 inch over the average, 

 or that which we regard as the average, viz., 27 "145 inches. (See Table I.) 



With respect to the eight-inch raingauge belonging to the Club, I am now, 

 quite satisfied that the instrument is perfectly correct in itself, and that the 

 eiTor alluded to in our report for 1866 is due to situation alone. This raingauge 

 has been removed from the Blue School play-ground and is placed in Mr. 

 Davison's garden near the White Cross ; it is examined daily at 9 a.m. and 

 the quantities are carefully recorded. 



I have recently placed a five-inch gauge in the stand at the Blue School, 

 but the amount of rainfall collected is always a little less than that caught by 

 the other Hereford gauges. The wnd appears in some way to affect raingauges 

 more at this point than at any other which I have tried in the neighbourhood 

 of Hereford. 



The Ozone observations (Table 3) have been carried on by Rev. H. C. Key, 

 and duly recorded, since May 2nd, 1867. The results will be found in the 

 table (3). We h.ive found home made test papers far better than those pm-chased 

 in London ; and of all formul:e given for the preparation of ozone paper, I find 

 that fm-nished by Dr. Kemp to be by far the best. Dr. Kemp's formula is as 

 follows : — Bibulous paper, white, tested for chlorine and hyposulphite of soda : 

 these to be removed by washing if present. Then make the following mixture, 

 pure starch 8 grains, iodide of potassium 10 grains, boiling water 1 ounce. Mix 

 and boil together. Satui-ate the paper and dry rapidly before a good fire but 

 without scorching. 



To this I would add that I have found the white blotting p.aper sold by 

 Mr. Head, of this city, perfectly free from impurities. I choose a strong sort 

 because it is less liable to tear when wet, and heavy with the starch. It is 



