282 



Abstracts of the Makerstoun Observations, 1843. 



The monthly means exceed the means of the highest and lowest readings in each month excepting May, 

 the mean of the twelve monthly maxima and minima being 0-118 in. less than the mean for the year. 



The monthly means exceed the means of the highest and lowest daily means in each month with the ex- 

 ceptions of May and November ; the mean of the twelve monthly maxima and minima of daily means being 

 0*069 in. less than the mean for the year.* 



TABLE XX.— Daily, Weekly, and Monthly Means of the Pressure of the Dry Air in 1843. 



Civil 

 Day. 



Jan. 



Feb. 



March. 



April. 



May. 



June. 



July. 



Aug. 



Sept. 



Oct. 



Nov. 



Dec. 





in. 



in. 



in. 



in. 



in. 



in. 



in. 



in. 



in. 



in. 



in. 



in. 



1 



[ ] 



29-035 



29-468 



28-704 



29-920 



29-009 



29-184 



29-102 



29-576 



[29-353] 



29-322 



29-712 



2 



29-747 



28-910 



29-714 



[28-968] 



29-814 



28-700 



[29-159] 



28-854 



29-549 



29-400 



29-409 



29-640 



3 



29-710 



28-748 



29-849 



29-097 



29-436 



28-911 



29-067 



28-716 



[29-637] 



29-443 



29-126 



[29-577] 



4 



29-263 



29-296 



29-951 



28-906 



29-113 



[29-094] 



29-315 



28-773 



29-756 



29-371 



29-032 



29-624 



5 



29-440 



[29-359] 



[29-824] 



29-129 



29-045 



29-429 



28-987 



29-080 



29-808 



29-298 



[29-140] 



29-277 



6 



29-502 



29-678 



29-685 



29-049 



29-025 



29-392 



28-983 



[29-132] 



29-565 



28-787 



29-144 



29-583 



7 



29-072 



29-785 



29-781 



28-783 



[29-286] 



29-127 



29-195 



29-403 



29-676 



28-697 



28-982 



29-368 



8 



[28-917] 



29-738 



29-962 



28-904 



29-328 



28-515 



29-300 



29-340 



29-638 



[28-964] 



29-148 



29-607 



9 



28-763 



29-792 



29-914 



[29-224] 



29-478 



28-504 



[29-347] 



29-482 



29-543 



29-062 



29-411 



29-689 



10 



28-266 



29-800 



29-596 



29-528 



29-727 



29-107 



29-480 



29-565 



[29-574] 



29-262 



29-078 



[29-650] 



11 



28-458 



29-830 



29-589 



29-612 



29-711 



[29-175] 



29-648 



29-567 



29-319 



28-680 



29-557 



29-656 



12 



28-528 



[29-593] 



[29-413] 



29-465 



29-495 



29-687 



29-477 



29-569 



29-618 



28-858 



[29-543] 



29-820 



13 



27-820 



29-605 



29-012 



29-528 



29-141 



29-644 



29-410 



[29-488] 



29-646 



29-112 



29-716 



29-757 



14 



28-233 



29-416 



28-995 



29-185 



[29-320] 



29-596 



29-412 



29-492 



29-403 



29-360 



29-883 



29-657 



15 



[28-847] 



29-117 



29-373 



29-463 



29-101 



29-621 



29-341 



29-372 



29-309 



[29-223] 



29-612 



29-562 



16 



29-261 



28-972 



29-497 



[29-423] 



29-103 



29-583 



[29-303] 



29-357 



29-363 



29-201 



29-588 



29-837 



17 



29-548 



29-277 



29-236 



29-487 



29-369 



29-557 



29-440 



29-349 



[29-429] 



29-164 



29-111 



[29-754] 



18 



29-692 



29-443 



29-368 



29-511 



29-602 



[29-544] 



29-105 



29-374 



29-390 



29-644 



28-858 



29-902 



19 



29-875 



[29-174] 



[29-198] 



29-362 



29-6.39 



29-536 



29-109 



29-150 



29-702 



29-928 



[28-983] 



29-874 



20 



29-776 



29-160 



29-301 



29-248 



29-489 



29-588 



28-975 



[29-136] 



29-406 



29-518 



28-848 



29-694 



21 



29-556 



29-107 



28-925 



29-241 



[29-417] 



29-377 



29-023 



29-268 



29-532 



29-331 



28-771 



29-776 



22 



[29-475] 



29-082 



28-859 



29-233 



29-251 



29-490 



28-965 



28-747 



29-882 



[29-319] 



28-724 



29-476 



23 



29-292 



29-167 



28-947 



[29-230] 



29-277 



29-492 



[29-226] 



28-931 



29-943 



29-214 



28-970 



29-611 



24 



29-084 



29-328 



29-333 



29-537 



29-243 



29-514 



29-485 



29-167 



[29-703] 



29-002 



29-157 



[29-720] 



25 



29-265 



29-374 



29-637 



29-031 



28-989 



[29-419] 



29-559 



29-137 



29-818 



28-921 



29-209 



29-805 



26 



29-353 



[29-2031 



[29-463] 



29-091 



28-884 



29-420 



29-350 



29-236 



29-671 



29-078 



[29-201] 



29-808 



27 



29030 



28-846 



29-618 



29-345 



28-813 



29-331 



29-368 



[29-270] 



29-372 



29-095 



28-776 



29-842 



28 



29-036 



29-034 



29-600 



29126 



[29-149] 



24-269 



29-293 



29-107 



29405 



28-322 



29-348 



29-899 



29 



[29-081] 





29-646 



29-304 



29-469 



29-227 



28-838 



29-357 



29-417 



[28-990] 



29-747 



29-787 



30 



29-001 





29-212 



[29-491] 



29-499 



29-172 



[29-109] 



29-611 



29-082 



29-058 



29-626 



29-511 



31 



29030 





28-764 





29-238 





29-199 



29-566 





29-063 





[29-463] 



Mean 



29-138 



29-314 



29-438 



29-235 



29-341 



29-300 



29-250 



29-247 



29-553 



29-149 



29-237 29-683 



This Table has been formed by subtracting Table IX. from Table XV. 



Annual Variation of the Pressure of Dry Air. — The pressure of the dry air is least in January, being 

 29138 in. ; it increases from thence till March, then diminishes in April ; after a slight increase in May it 

 diminishes till August, the pressure being nearly the same in that month as in April ; it then mcreases con- 

 siderably in September, and diminishes to a greater extent in October and November ; the greatest pressure 

 occurs in December, being 29-683 in. The range of the monthly means is therefore 0-545 in. If the pressure 

 in December be kept ovit of view, the annual variation for 1843 indicates maxima in the equinoctial months, 

 and minima near the solstices. The following are the means for the three different gToups, namely. 



* I have pointed out elsewhere (Transactions of Sections, Report of Brit. Assoc. 18-45, p. 15), that the means of the monthly 

 maxima and minima are probably always less than the mean pressure in certain latitudes (including 50° and 60° north), but that in 

 other latitudes the reverse is the case. The explanation of this fact will probably be found in the prevalence and excessive j)ressures 

 of particular winds. 



