216 



RECORD AND RESULTS OF 



Resulting monthly averages of bi-hourly observations of the barometer ; temperature reduced 



to 32°. 





2" 



4 



6 



8 



10 



Noon 



2 



4 



6 



8 



10 



12" 



September 



October 



November 



December 



January 



February 



March 



April 



May 



June 



July 



29.690 

 .563 



.101 



29.681 

 .584 



.101 



29.685 

 .592 



.611 



29.695 



.616 



30.086 



.051 



29 835 



.150 



.816 



30.059 



30.000 



29.689 



.611 



29.619 

 .616 



30.086 

 .039 



29.825 

 .151 

 .801 



30.051 



29.981 

 .680 

 .681 



29.682 

 .619 



30.019 

 .029 



29.821 

 .139 

 .811 



30.056 



29.983 

 .610 

 .690 



29.684 

 .618 



30.088 

 .035 



29.832 

 .134 

 .801 



30.050 



29.981 

 .614 

 .686 



29.689 

 .618 



30.081 

 .036 



29.842 

 .141 

 .812 



30.051 



29.985 

 .611 

 .688 



29.681 

 .611 



30.096 

 .031 



29.844 

 .156 

 .835 



30.066 



29.986 

 .681 

 .130 



29.686 



, .625 



30.094 



.022 



29.843 



.162 



.834 



30.010 



29.985 



.682 



.688 



29.685 

 .629 



30.094 

 .023 



29.841 

 .159 

 .832 



30.013 



29.989 

 .619 

 .101 



29.686 

 .658 



.61( 



Diurnal Fluctuation of the Atmosplieric Pressure. 



The diurnal fluctuation, on the yearly average, was deduced from the above 

 table as follows : The readings for August were interpolated from the July and Sep- 

 tember readings ; from the observations at Van Rensselaer Harbor, Port Kennedy, 

 and Baffin Bay, August mean = July mean — 0'°.009, also August mean = Septem- 

 ber mean — 0'''.040 ; applying these reductions, and taking the mean of the two 

 results, we find for August the readings : — 





2" 



4 



6 



8 



10 



Noon 



2 



4 



6 



8 



10 



12'^ 



August 



29.614 



29.610 



29.656 29.658 



29.658 



29.661 



29.661 



29.064 



29.684 



29.662 



29.668 



29.656 



To supply the annual means for the hours midnight, 2, 4, 6 A. M., we have mean 

 of 8, 10, noon, 2, 4, 6, 8, 10 for July, August, September, October =29.668, and for 

 the same hours, mean of the year =29.828, hence correction to the means of four 

 months at the hours midnight, 2, 4, 6 A. M. to refer them to the annual value 

 = -I- .160. 



We have consequently for the whole year : — 





2i> 



4 



6 



8 



10 Noon 



2 



4 



6 



8 



10 



121' 



Year 



29.818 



29.820 



29.812 



29.826 



29.822 29.&20 



29.820 



29.825 



29.835 



29.829 



29.831 



29.829 



If we subtract from these numbers their average value, we find the diurnal 

 variation proper as given below, to which that of Van Rensselaer Harbor, Port 

 Kennedy, and Baffin Bay (^ = 72.5) have been added. 



