54 



myself; while it shows that the Garden at the Institution 

 is not so very unfavourable a spot for determining high 

 summer temperatures. What it may be in respect of low 

 temperatures in winter, I am not prepared to say at present. 

 Mr. Weston has suggested one reason why it may have been 

 hotter on the above days at Ensleigh than in the lower parts of 

 Bath, which is probably the true one. He attributes it to the 

 solar radiation, which on those days was very great, especially 

 on the 15th, when it was excessive, amounting at Ensleigh to 

 140°, the highest during the month. Unfortunately, we have 

 not the means of determining the heat of the sun's rays in the 

 Institution Gardens, there being no suitable spot where a 

 proper thermometer for the purpose could be placed ; but we 

 might expect that, so low down as these Gardens are, and so 

 near the river, the air would always be in a more humid 

 state than higher up, and its transparency proportionably 

 diminished. And that such is the case would seem to be 

 shown by the circumstance of the mean temperature of the 

 dew point for the whole month of July being very nearly one 

 degree higher in the Institution Gardens than at Ensleigh. 

 On that particular day, the 15th, the temperature of the dew 

 point at Ensleigh at 9 a.m. was 5 9°. 6, being a depression below 

 the temperature of the air of 15°.9 ; in the Institution Gar- 

 dens, at the same hour, the dew point was 65°. 6, or 6° higher, 

 with a depression of only 10° ; and this difference in the 

 temperature of the dew point was kept up throughout the 

 day, remaining a constant quantity, though of course, at both 

 places, the temperature of the dew point itself varied with 

 the hour. This fact is quite sufficient to show the greater 

 humidity of the town, compared with the higher part of the 

 downs, at least on that particular occasion. 



Mr. Weston, in his letter to me, makes an interesting 

 remark on the appearance of Bath on a fine summer's morn- 

 ing from the elevated spot on which his house stands. He 



