474 



DISCUSSION OF BAEOMETKIC OBSERVATIONS. 



of Wolf's series (that is, the mean of Wolf's numbers for 1836 and 1837 

 is taken as the sun-spot number for the year 1836-'37, the mean of the 

 given numbers for 1837 and 1838 as the number for 1837-'38, etc.). In 

 this comparison the observations for the years 1836 to 1853, hitherto 

 omitted from this discussion, are included ; for though in respect to the 

 absolute values of pressure these observations are not comparable with 

 the later ones, they may be considered -as fairly comparable as far as 

 range is concerned, though less accurate. 



Table VII. 

 Variation of the Annual Barometric Range. 



Year. 



1836-'37 . 

 1837-38 . 

 1838-'39 . 

 1839-'40 . 

 18-i0-'41 . 

 1841-'42 . 

 1842-'43 . 

 1843-44 . 

 1844-'45 . 

 1845-'46 . 

 lS46-'47 . 

 1847-'48 . 

 1848-'49 . 



1849-'50 . 



1850-' 

 1851-' 

 1852-' 

 1853-' 

 1854-' 

 1855-^ 

 1856-' 

 1857-' 

 1858-' 

 1859-' 

 I860-' 

 1861-' 

 1862-' 

 1865-' 

 1864-' 

 1865-' 

 1866-' 

 1867- 

 1868-' 

 18G9-' 

 1870- 

 1871-' 

 1872-' 

 1873-' 

 1874- 

 1875-' 

 1876-' 

 1877-' 

 1878-' 



Months of 

 extremea. 



Apr 

 Oct. 

 Dec. 

 Oct.- 

 Oct. 

 Feb. 



Feb.- 



Feb. 



Feb.- 



Dec 



Nov 



Jan. 



Dec 



Feb, 



Jan. 



Dec. 



Dec. 



Jan. 



Jan 



Feb. 



Dec. 



Dec. 



Jan.- 



Feb. 



Feb. 



Oct.- 



Jan." 



Jau.- 



Deo 



Jan.- 



Feb. 



Dec. 



Feb. 



Dec. 



Jan. 



Feb. 



-Jan. 

 -Dec. 

 -Oct. 

 -Mar. 

 -Feb. 

 -Apr. 



(Feb. 



) Mar. 



-Dec. 



-Apr. 



-Jan. 



.-Dec. 



-Dec. 



.-Dec. 



-Dec. 



-Oct. 



-Mar. 



Feb. 

 -Feb. 

 -Feb. 



-Apr. 



-Feb. 



-Dec. 



-Apr. 



-Dec. 



-Apr. 

 -Dec. 

 -J.an. 

 -Feb. 

 -Feb. 



Mar. 



■Nov. 



-Nov. 



-Feb. 



■Dec. 



■Mar. 



-Dec. 



a 



30.38 

 30.32 

 30.69 

 30.40 

 30.42 

 30.41 

 30.48 

 30.58 

 30.34 

 30.54 

 30.48 

 30.42 

 30.45 



30.50 



30. 58 

 30. 423 

 30. 486 

 30. 463 

 30. 664 

 30. 381 

 30. 687 

 30. 569 

 30. 446 

 30. 427 

 30. 431 

 30. 549 

 30. 718 

 30. 419 

 30. 340 

 30. 672 

 30. 584 

 30. 526 

 30. 363 

 30. 380 

 30. 428 

 30. 323 

 30. 387 

 30. 453 

 30. 372 

 30. 629 

 30. 320 

 30. 374 

 30. 458 



a 



28.50 

 28. 61 

 29.00 

 28.40 

 28.77 

 28.75 

 28.80 

 28.61 

 28.60 

 28.90 

 28.40 

 28.88 

 29.10 



28.90 



28.64 

 28. 605 

 28. 546 

 28. 799 

 28. 695 

 28. 640 

 28. 773 

 28. 846 

 28. 817 

 28. 948 

 28. 787 

 28. 779 

 28. 970 

 28. 919 

 28. 703 

 28. 637 

 28. 543 

 28. 755 

 28. 681 

 28. 820 



28. 869 



29. 036 

 28. 645 

 28. 509 

 28. 807 

 28. 621 

 28. 824 

 28. 764 

 28. 641 



1.88 

 1.71 

 1.69 

 2.00 

 1.65 

 1.66 

 1.68 

 1.97 

 1.74 

 1.64 

 2.08 

 1.54 

 1.35 



1.60 



1.94 

 1 818 

 1.830 

 1.664 

 1.969 

 1.741 

 1.914 

 1. 723 



1. 629 

 1.479 

 1.644 

 1.770 

 1.748 

 1.500 

 1.637 



2. 035 

 2.041 

 1.771 

 1. 682 

 1. 560 

 1.559 

 1.287 

 1.742 

 1.944 

 1.565 

 2.008 

 1.496 

 1.610 

 1.817 



1.78 

 1.79 

 1.74 

 1.70 

 1.75 

 1.80 

 1.79 

 1.79 

 1.77 

 1.64 

 1.54 



1.63 



1.78 



1.83 



1.801 



1.796 



1. 823 



1.835 



1.809 



1.733 



1.634 



1.591 



1.640 



1.698 



1.670 



1.646 



1.734 



1.887 



1. 924 



1.819 



1.688 



1.586 



1.510 



1. 527 



1.656 



1.762 



1.777 



1.740 



1.677 



103.8 

 96.8 

 75.5 

 60.1 

 40.7 

 24.6 

 14.0 



*10. 8 

 23.0 

 40.0 

 63.2 

 89.9 



t98.0 



80.0 



63.2 

 57.0 

 45.0 

 28.4 

 13.0 

 *5.5 

 12.9 

 36.2 

 73.6 



t97. 5 

 88.0 

 68.4 

 51.9 

 45.7 

 39.8 

 25.0 



*12.7 

 24.1 

 62.1 



111.8 

 tl24. 6 



105.6 

 84.0 

 55.5 

 30.8 

 14.2 

 11.8 

 7.9 



In this table a relation between the mean range and the sun-spot 

 numbers is obvious at a glance, not a single maximum or minimum of 

 the latter series failing to fall on the same year with an opposite phase 



"Years of miuimum sun-spots, and maximum barometric range, 

 t Years of maximum sun-spots, and minimum barometric range. 



