422 



Results of Makeestoun Observations, 1844. 



These means vai-y witli great regularity. The diurnal range of atmospheric pi-essure was greatest when 

 tlie moon was farthest north, and it was least when the moon was farthest south. The mean of 84 diurnal 

 ranges about the time of the moon's greatest northerly position was 0-052 in. greater than the mean of the 

 same number of ranges about the time of the moon's greatest southerly position. 



TABLE XXI. — Hourly Means of the Height of the Barometer for each Month, and the Year 1844. 



Mak. 

 M. T. 



h. 



12 



13 



14 



15 



16 



17 



18 



19 



20 



21 



22 



23 







1 



2 



3 



4 



5 



6 



9 

 10 

 11 



29-695 

 •691 

 ■690 

 •690 

 •686 

 •684 

 •684 

 •687 

 •695 

 •701 

 •706 

 •698 

 ■692 

 ■686 

 •685 

 •689 

 •692 

 •694 

 •697 

 •700 

 •698 

 •700 

 •700 

 •694 



29 



307 

 •300 

 •295 

 •290 

 •287 

 •289 

 •290 

 •299 

 ■312 



• 318 

 •325 

 •334 



• 336 

 •336 

 •333 

 •333 

 •334 



• 337 

 •340 



■ 344 

 •343 

 •340 



■ 337 

 ■336 



29 



March. 



511 

 511 

 506 

 504 

 506 

 507 

 511 

 513 

 517 

 523 

 526 

 529 

 528 

 526 

 527 

 528 

 533 

 542 

 549 

 557 

 556 

 558 

 559 

 561 



29 



April. 



811 

 •805 

 •802 

 •800 

 •796 

 •802 

 •807 

 •811 

 •812 

 •811 

 •809 

 ■805 

 •802 

 •801 

 •795 

 •793 

 •794 

 •794 

 •799 

 •806 

 •812 

 •814 

 • 814 

 ■ 814 



May. 



29- 



988 

 •982 

 •981 

 •978 

 •981 

 •987 

 •991 

 •995 

 •997 

 •996 

 •993 

 •988 

 • 982 

 •977 

 •970 

 •962 

 •959 

 •959 

 •962 

 •970 

 •978 

 •983 

 •983 

 •983 



29 



June. 



631 

 629 

 623 

 621 

 624 

 628 

 631 

 632 

 635 

 635 

 634 

 629 

 630 

 627 

 625 

 624 

 621 

 617 

 620 

 622 

 625 

 627 

 625 

 626 



July. 



29641 

 •638 

 •633 

 •629 

 •632 

 •635 

 •638 

 •638 

 •637 

 •635 

 •629 

 ■630 

 •629 

 •629 

 •621 

 •616 

 •609 

 •603 

 •603 

 •607 

 •611 

 ■616 

 •621 

 •622 



Aug. 



29^493 

 •489 

 •483 

 ■478 

 ■475 

 •479 

 ■485 

 ■488 

 ■489 

 490 

 ■489 

 ■490 

 ■487 

 ■486 

 ■486 

 ■485 

 ■485 

 ■484 

 ■489 

 ■494 

 •500 

 •504 

 •507 

 •507 



Sept. 



Oct. 



29-828 

 •825 

 •819 

 •814 

 •811 

 •812 

 •820 

 •825 

 •827 

 ■830 

 •826 

 •821 

 ■817 

 •813 

 ■806 

 •803 

 •801 

 •803 

 •808 

 •815 

 •819 

 ■818 

 ■821 

 ■819 



29 



•397 

 •392 

 •385 

 •378 

 •375 

 •374 

 •376 

 •387 

 •395 

 •400 

 •401 

 •401 

 •397 

 •396 

 •397 

 •394 

 ■399 

 ■404 

 •412 

 •414 

 •418 

 •416 

 •412 

 •406 



Nov. 



29553 

 •549 

 •548 

 •544 

 •545 

 •544 

 •544 

 •550 

 •559 

 •565 

 •572 

 • 572 

 •567 

 •564 

 •562 

 •564 

 •565 

 •569 

 •573 

 •575 

 •577 

 •579 

 •580 

 •582 



29 



Dec. 



892 

 887 

 888 

 885 

 879 

 876 

 878 

 883 

 891 

 899 

 904 

 899 

 889 

 884 

 884 

 887 

 888 

 890 

 893 

 899 

 903 

 905 

 907 

 907 



29 



•6456 

 •6415 

 •6377 

 •6342 

 •6331 

 •6.347 

 •6379 

 ■6423 

 •6472 

 ■6502 

 ■ 6512 

 ■6497 

 ■6463 

 •6437 

 •6409 

 •6398 

 ■6400 

 ■6413 

 ■6454 

 ■6502 

 ■6533 

 ■6550 

 ■6555 

 •6547 



Diurnal Variation of Atmospheric Pressure. — The means for each month indicate two maxima and two 

 minima ; the epochs, however, vary considerably ; this is chiefly due to rapid variations of mean pressure, and 

 especially to those which occur between Saturday night and Monday morning ; these render the mean at 1 1*" 

 (the hour of the last observation on Saturday) considerably different from that at 12'> (the hour of the first 

 observation on Monday morning). Assuming that the change in the means from U*" to 12'' is the same as 

 from lO"" to IP, the differences between the means for 12'i so obtained, and tlie means for 12'' at the com- 

 mencement of each series, will be due to the causes noticed above, and they may be considered as differences 

 which have gradually increased from tlie first to the following 12". By correcting the observations for such 

 o-radual changes, the epoch.s of maxima and minima will be determined with more accuracy. Table XXII. 

 has been formed in tliis way. The hourly means of the astronomical quarters having been obtained, the change 

 from the preceding to the following 12'' was found — 



For Winter, =+0^0131. 

 Tor Spring, =-f 0-0270. 



Correction, = — 0^00055 an hour. 

 =-000112 



For Summer, = - 

 For Autumn, =: 



0^0090. 

 0^0000. 



Correction, = +0-00037 an hour. 



For the means for the year, = -f 0-0083. Correction, = —0-00035 an hour. 



The number of the hour after 12'' being n, the hourly means for the quarters were corrected by the quan- 

 tities 11 X c, where c is the correction given above for the respective quarters ; the numbers for each quarter 

 and the year, in excess of the lowest mean thus corrected, are given in Table XXII. 



i 



