RECORD AND DISCUSSION OF TEMPERATURES. 



35 



sum of the above differences for the hours during which snow fell, the second 

 column the number of hours, and the last column the rise of temperature above 

 the mean. In 17 months, it snowed during 680 hours, and rained during 60 hours. 

 This small quantity of rain fell in the month of July ; snow also fell during 10 

 hours in this (warmest) month. 



On the average, during the whole year, the sensible heat was increased during 

 the fall of snow by 7. 7. 



The bearing of this source of change of the temperature on the alternation of 

 relative cold and warm periods during the winter season, will be further illustrated 

 in the following analyses of these undulations. 



Recurrence of Maxima of Cold during Winter. An alternate variation from com 

 paratively warmer to colder extremes, taking weeks to perform their cycles, has 

 before been noticed in the arctic regions of America. These returns of maxima of 

 cold, their causes, periods, and amplitudes, now deserve our particular attention. 

 Dr. Kane, from various notes in his log-book, seems to be inclined to consider the 

 phases of the moon as intimately connected with the subject ; on page 55, Vol. II. 

 of the Narrative, he remarks: &quot;There is a seeming connection between the increas 

 ing cold and the increasing moonlight.&quot; Under date Nov. 28th, 1854, he entered 

 the following remark in the log: &quot; The moon first appeared above the hills to S. 

 and S. E. The depression of the temperature, and the general transparency of the 

 atmosphere, is again noted as material for discussion.&quot; Dec. 1st, 1854, he says: 

 &quot;With the cessation of wind, the absence of cirri, and the increased brightness of 

 the moon, the atmosphere grows sensibly colder. * * This immediate influ 



ence of the moon is a matter of frequent observation. The full moon season, with 

 cloudless nights is always in correspondence with the lowest mean temperatures of 

 our meteorological record.&quot; The following discussion has been made in accordance 

 with these notes. 



To eliminate as much as possible disturbing influences, particularly those pro 

 duced by the winds and precipitations, the average of the mean daily temperature 

 of a number of consecutive days has been taken, and it was found, after trials 

 with 3, 5, 6, and 7 days, that the period of 6 days answered best, that is, brought 

 out in the plainest manner, the march of the temperature during the winter season, 

 the general features of the curves being the same for any of the above periods. 



The epoch of the 6 day period was so selected that the highest and lowest tem 

 peratures should, as near as may be, fall towards the middle of a period. These 

 average values were next compared with the mean temperature deduced from the 

 half monthly means in order to exhibit the deviation of the observed average values 



