DISCUSSION OF BAROMETRIC OBSERVATIONS. 



Table IV. 



Computed normal pressure for every day in the year. 



[Tenth order of means' from Table n.] 



469 



Day of the month. 



1 



2 



3 



4 



5 



6 



7 



8 



9 



10 



11 



12 



13 



14 



15 



16 



17 



18 



19 



20 



21 



22. 



23 



24 



25 



26 



27 



28. 



29 



30. 



31. 



697 



681 



075 



685 



701 



711 



708 



696+ 



689 



691 



704 



720+ 



732 + 



731+ 



715 



693 



677+ 



674-1- 



674 



667 



654 



641 



633 



628 



624 



620 



619+ 



624 + 



632 



638 



645 



656 



671 



681 



682 



678 



684 



706 



731 



741+ 



732 



713 



695+ 



686+ 



683 



683 



684 



685 



682 



672 



656 



643 



638+ 



644 



656 + 



670 + 



683 



690 



689 



681 



669 



714 



713+ 



710 



706 



703 + 



702 



699 



694 



690+ 



693 



703 



715 



725 



731 



735 



740 



745 



746+ 



746+ 



746 



745+ 



745 + 



746+ 



749 



753 



754 



749 



738 



729 



728+ 



737 



750 

 762 

 773 



784 



796 



809 



820 



825 



820 



807+ 



795+ 



793 



803 + 



816 



818 + 



807 



787 



770 



766 



778+ 



803 



824+ 



829+ 



814 



790 



774+ 



774 



784 



790 



784 



765 



742+ 



728+ 



729 



741 



755 



764 



765 



760+ 



751 + 



741 



732 



725 



721 



720 + 



724 



727 



728+ 



730 



738 



752+ 



772 + 



794 



810 



810+ 



793 



769 



753 



748 



748 



747+ 



746 



745 + 



749 



754 



759 



757+ 



747 



732 



719 



714 



713 



716+ 



723 



731 



731 



72e 



703 



688+ 



684 



685 



689 



689 



687 



684+ 



682 



677+ 



667 



652 



645 



655 



679 



704 



718 



723 



723 



720 



710 



710+ 



723+ 



734 + 



747 



759 



770 



779+ 



786 



790 



703 



796+ 



797 



791 



780 



768 



761 



761 



763 



761 



759+ 



765 



778 



792 



800 



On applying the test of Mr. De Forest to this series the total number 

 of signs occuring in groujjs of three or more is found to be less than half 

 the whole number of terms by 18 — a diiference much less than that of 

 Table I, though nearly double the probable difference of a perfect 

 adjustment. 



In respect to the treatment of the 29th of February, this table is less 

 accurate than the others ; for the pressure for that dat«, as derived from 

 Table II, should in strictness have been allowed only one-fourth of the 

 weight of the other values ; but as such a discrimination could not con- 

 veniently be made in the computation, the 29th was treated precisely 

 like the adjacent dates. In all the other tables due allowance is made 

 for the peculiarity of that date. 



The sign + appended to numbers in Table IV indicates a fraction be- 

 tween -j^o^ and -fiPv' Smaller fractions are disregarded, and for larger ones 

 the third figure is increased by 1. 



MEAJSr DEPARTURE FROM NORMAL VALUE, AND PROBABLE ERROR. 



In describing the method of deriving the numbers which constitute 

 Table II it was shown that for each day of the year, along with the 

 mean pressure, another number was deduced, which was called "the 



