xe GENERAL RESULTS OF THE MAKERSTOUN OBSERVATIONS. 
TABLE 82.—Diurnal Variation of the Relative Humidity of the Air, for each Astronomical Season 
. and for the Year, deduced from the Observations of the Years 1843-6. 
Mak. || : Feb. May. Aug. Mak. Nov. Feb. May. Aug. 
Mean Dec. March. | June. Sept. Year. Mean Dec. March. | June. Sept. Year. 
Time. Jan. April. July. Oct. Time. Jan. April. | July. Oct. © : 
(am | a h. m. inna: 
12 10 | +0-013 |+0-061 |+0-103 | + 0-072 | +0-062} O 10 |—0-035 —0-090 |—0-109 | —0-106 |—0-085 
13 10 ||+ -014\+ -065|+ -105|+ -075/+ -065] 1 10 |— -043|— -107/— -118|— -122))— .097 
14 10 |4+ -012)+ -069|+ -105|/+ -072,)|+ -064] 2 10 |— -044)— -110)— -112|}—°-130)|;— -099 
15 10 |4+ -014\+ -065)+ -109)+ 078 ||+ -066) 3 10 |— -027|— -106)— -112}— -120)/— -091 
16 10 |+ -017|-+ -064/+ -101/+ -075|/+ -064] 4 10 /— -009|— -090)— -102/— -096||— .074 
17 10 ||+ -018|+ -066)+ -087)+ -072||+ -061} 5 10 |/+ -001)— -052)— -079|— -058|/— -047 
18 10 ||-+ -022)4+ -058|+ -062|+ -064))+ -O51] 6 10 + -003|— -027 — -051\)— .016)|\— .023 
19 10 |+ -019|+ -050|+ -023/4+ -052)+ -036] 7 10 |+ -003|+ -009|— -012\+ -018)|+ -004 
20 10 |+ -021|4+ -027/— -017/+ -019]/+ -012] 8 10 |+ -007|+ .028/+ -031/+4 -038|/+ -026 
21 10 |+ -007|— -010/— -054|— -019||— -019} 9 10 + -009|+ -037\+ -059 + -051 + -039 
22 10 |— -005|— -054|— -077|— -057)}— -048] 10 10 |/+ -007|+ -053)+ -078\+ -060)+ .049 
23 10 |— -027|/— -073|— -103|— -085])/— -072] 11 10 |\+ -004|/+ -060)+ -088\+ -057)+ .052 
188, Diurnal Variation of the Relative Humidity —The following are the approximate epochs of maxima 
and minima, as obtained from Table 82. 
Winter, Noy., Dee., Jan., Maximum 7" 4.m. Minimum 1" 50™ p.m, 
Spring, March, April, May, Siete» , caer 1» 50™ p.m. 
Summer, June, July, Aug., BEMASAE. inc rosso cis 1» 20m p.m. 
Autumn, Sept., Oct., Nov.,  ....--- REAM EU AGM lh cncimerent oe Osea 
Year, ." Siu hetytereses: TAC fo 32 i ogo eee 1h 40™ p.m. 
The diurnal variation of relative humidity is nearly the inverse of that of the temperature of the air. 
The mean relative humidity occurs at 8" 33™ A.M., and at 7" 1™ p.m., the interval being 102 28m, 
The range of the diurnal variation is least in winter, = 0-066 ; it is*greatest in summer, = 0:227; the 
values of the range for spring being 0-179, and for autumn being 0:208. 
ATMOSPHERIC PRESSURE. 
189. The Mean Pressure of the Atmosphere at Makerstoun, 213 feet above the mean level of the sea, as 
deduced from the observations in the 8 years 1842-9, = 29-615 inches of mercury at 32° Fahrenheit, measured 
on brass at 62° Fahrenheit ; with a probable error of 0-009 inch, each year’s mean receiving an equal weight. 
The mean pressure for any future year = 29-610 inches, with a probable error of 0-026 inch.* 
TABLE 83.—Monthly Means of the Atmospheric Pressure at Makerstoun, for the Years 1841-9. 
Mean of 8 Years. 
Month. 1841. 1842, 1843. 1844. 1845. 1846. 1847. 1848, 1849. ® Mean 
Height of Tevet 
213 feet. 
| of Sea. 
in. in. in. in. in. in. | in. in. in. in. 
Jan. || 29-584 | 29-357 | 29-693 | 29-512 | 29-392 | 29-604 | 29-722 | 29-508 || 29-547 | 29-786 
Feb. | -611 -499 +321 -704 -617 -625 194 “819 +549 -788 
March | -485 -662 +529 ‘741 -406 775 +354 +755 -588 +826 
April | | 946 -487.| -805 -642 535 455 595 -450 -614 +850 
May | -626 -620 -980 ‘703 +648 “099 ‘770 -796 ‘718 “951 
June | -764 “619 -627 +597 -706 *672 475 ‘735 649 879° 
July | | +665 -635 +625 +622 +556 “794 ‘619 +583 -637 +865 
Aug. 29-567 | -723 656 -489 578 -691 ‘751 +526 658 -634 +863 
Sept. -483 +652 +935 817 +645 +732 -605 ‘717 -792 “737 -970 
Oct. | -o72 +682 -401 +397 +602 +312 +646 551 -606 +525 ‘758 
Nov. || -453 -448 | 471 363 | +323 +655 +643 “601 -530 +529 -765 
% All the observations are reduced to the mean of the flint and crown glass barometer of the Royal Society of London. In com- 
paring these results with others reduced to the flint-glass barometer only, a correction of + 0-003 in. should be applied, See Intro- 
duction 1844, page lv. 
