'\c% l Mr. Six' s Experiments 
the Weather is {fill and warm, the difference of temperature 
is reverfed, the reflection of the fun’s rays from the earth 
heating the air more below than it does above. 
The experiments in my former Paper * were made partly in 
autumn, and partly in winter ; and, the local variations dif- 
fering in fome meafure with the feafons, I was defirous of 
continuing a feries of experiments throughout one entire year* 
To this end, therefore, I fufpended proper thermometers + in 
a fhadv northern al'pecf, in the open air, at different heights $ 
one in my garden at nine feet, and another in the Cathedral 
Tower 220 feet from the ground; continuing my journal* 
with the omiffion of a few days only, from July 1784 till 
July 1785. 
In the fummer of 1783, risking experiments with thermometers, which I had 
eonftrucled to (hew the greateft degrees of heat and cold that happened in the 
obierver’s abfence, I fir ft perceived this no&urnal refrigeration in the lowed drat uni 
of the atmofphere ; for by fufpending thefe thermometers at different altitudes, 
and viewing them only once in twenty- four hours, I found the true maximum 
and minimum of the heat and cold, which had happened during that time in 
’their feveral flations. 
*— e 
A writer irt the Gentleman’s Magazine, for March 1785, p. I70, who did me 
the honour to mention my former Paper, containing Experiments on Local Hcat> 
obferved, that the"effe£ts of a fliarp froft, which happened in December of tbepre - 
eedingyear , appeared to be much more fevere among the Vegetables in the vallies than 
On the hills ; an'd by taking the difference of temperature with thermometers at 
that time, he found them Vary from 5 to 1 7 degrees, according to their feveral 
ftations; 
M. oe Saussure, in his Voyages darts les Alpes, Vol. II. publiflied 1786, 
fays, “ Quant a l’obfervation biert curieufe et been nouvclle de M. Pictet, que pen- 
dant la nuit la couche d’air la plus bade depuis la terre jufques a 5 pieds au-defl"u? 
ed plus froide que les couches fuiVarttes depuis 5 pieds jufque a 30.” 
* Philofophical Tranfa&ions, Vol. LXXIV. p. 428. 
f Conftru&ed to give the true maximum and minimum that may happen in 
♦he obferver’s abfence. See Philofophical Tranfaftions* Vol, LXXII. p. 72. 
The 
