MAGNETIC OBSEKVATOR Y. 
153 
Our magnetic observations went on; but the cold 
made it almost impossible to adhere to them with regu¬ 
larity. Our observatory was, in fact, an ice-house of 
the coldest imaginable description. The absence of 
snow prevented our backing the walls with that im¬ 
portant non-conductor. Fires, buffalo-robes, and an 
arras of investing sail-cloth, were unavailing to bring 
THE OBSERVATORY. 
up the mean temperature to the freezing-point at the 
level of the magnetometer;* and it was quite common 
* We liad a good unifilar, that had been loaned to us by Professor 
Bache, of the Coast Survey, and a dip instrument, a Barrow’s circle, 
obtained from the Smithsonian Institution, through the kindness of 
Col. Sabine. I owe much to Mr. Sontog, Dr. Hayes, and Mr. Bon- 
sall, who bore the brunt of the term-day observations; it was only 
toward the close of the season that I was enabled to take my share 
