18 ANNIVERSARY ADDRESS. 
temperature of any part of the bore. First, in sinking-it, when » 
the temperature was to be taken, a smaller bore was driven in 
_ advance for several feet ; into this the thermometer was lowered, 
and a wooden plug driven into the top of the small bore, so as 
to prevent convection affecting the temperature. After the ther- 
mometer had remained in from twenty to thirty hours, it was 
withdrawn and read. The other method was, to cut off by means 
of two plugs sections of the well, in which a thermometer was 
Kept about the same number of hours. I give the results of 
these measures :-— 
T t - IT 
Depth se Difference. ina - for posieare, Difference. rors : 
Faht. scale. 100 feet. 
| 
#48°2 
721 206 POO a. OE | saaves 
927 206 743 374 Ny 
1,133 206. 79°6 53 2°7 
1,339 206 80°4 0-8 0°4 
1,5 84: 4-0 20 
1,751 206 87°6 3-2 16 
1,957 206 91°6 40 2°0 
2,163 206 96°5 4:9 25 
3,491 1,328 115'8 19°3 ° 15 
* Mean temperature of air at the well. 
This gives an average of 1° Faht. for every 51°5 English feet, and 
_the increase for the last 1,300 feet was not so = as in the 
higher levels. 
Turning now to the other extreme, we learn from Captain 
Marham’s letter to Commodore Hoskins, re Polar Expedition, 
that :-— 
“The cold up tothe end of February, 1876, was not felt 
severely, although the temperature was ranging from — 30° to 
— 60° ; but during the last few days of that month and beginning 
of March the cold was intense, the temperature falling as low 
as — 74°: This, I believe, is the lowest that has ever been 
recorded. In this temperature glycerine became perfectly solid 
“and quite transparent, rectified spirits of wine became of the 
2 
. 
| Gal es Ba AP RD tee Tals 50h RE aay) Sale EO Oe Ee SPIRIT coc BE) vi eR ea 
