406 



Results of Makerstoun Observations, 1844. 



TABLE II. — Hourly Means of the Temperature of the Air for each Month in 1844. 



Mak. 

 M. T. 



Jan. 



Feb. 



March. 



April. 



May. 



June. 



July. 



Aug. 



Sept. 



Oct. 



Nov. 



Dec. 



ii. 



o 



O 



o 



o 



o 



o 



o 



O 



o 







o 







12 



35-4 



29-9 



35-3 



42-0 



42-7 



49-6 



50-4 



500 



48-5 



42-9 



41-8 



31-4 



13 



35-4 



30-0 



35-2 



41-5 



42-6 



49-2 



49-5 



49-3 



48-1 



42-9 



421 



31-3 



14 



35-3 



29-6 



35-3 



40-8 



41-7 



48-8 



49-2 



490 



47-7 



42-3 



41-9 



31-2 



15 



351 



29-7 



34-9 



40-5 



41-3 



48-5 



48-8 



48-4 



47-2 



42-3 



41-8 



310 



16 



351 



29-7 



34-5 



40-2 



41-3 



49-1 



48-9 



48-0 



46-8 



42-2 



41-6 



30-9 



17 



34-7 



30-2 



34-2 



40-3 



42-4 



50-0 



50-2 



48-2 



46-9 



41-8 



417 



30-9 



18 



35-2 



301 



340 



41-7 



44-6 



51-7 



52-4 



500 



47-5 



421 



41-7 



30-8 



19 



35-7 



300 



351 



43-6 



46-8 



53-5 



54-7 



520 



49-8 



42-4 



41-7 



30-9 



20 



36-0 



30-5 



36-9 



46-1 



48-6 



551 



56-9 



54-3 



52-5 



44-3 



41-8 



30-8 



21 



36-5 



32-3 



38-9 



48-9 



50-4 



560 



58-1 



56-6 



54-8 



46-3 



42-9 



30-8 



22 



37-6 



34-2 



40-6 



51-6 



51-9 



57-9 



59-3 



58-4 



56-6 



48-3 



43-6 



31-7 



23 



38-9 



35-5 



41 -8 



52-9 



53-7 



59-8 



60-7 



59-8 



57-9 



50-0 



44-3 



32-6 







401 



361 



42-9 



53-7 



55-0 



59-9 



611 



60-9 



58-7 



511 



44-9 



33-5 



1 



40-6 



370 



43-4 



53-9 



55-8 



60-5 



61-2 



61-2 



591 



51-5 



45-3 



34-3 



2 



40-5 



37-0 



43-7 



54-1 



56-0 



59-8 



61-4 



611 



590 



51-6 



45-1 



33-9 



3 



39-7 



35-8 



43-6 



53-7 



55-9 



58-9 



61-7 



61-0 



58-5 



50-6 



44-2 



32-9 



4 



38-4 



34-6 



42-6 



52-3 



550 



58-4 



60-8 



60-5 



57-3 



49-2 



43-3 



31-9 



5 



37-6 



32-9 



40-9 



50-8 



53-6 



57-4 



60-0 



58-5 



55-4 



47-1 



42-5 



31-6 



6 



36-7 



32-2 



391 



490 



51-8 



56-0 



58-7 



56-9 



53-9 



46-1 



42-4 



31-2 



7 



36-6 



31-9 



38-1 



46-6 



49-6 



54-7 



571 



54-6 



52-6 



45-3 



42-4 



31-2 



8 



36-4 



31-4 



37-2 



45-4 



47-4 



531 



54-8 



531 



51-2 



44-8 



41-9 



310 



9 



36-4 



31-1 



36-5 



43-8 



45-9 



51-9 



53-5 



51-7 



50-5 



43-9 



41-6 



311 



10 



36-1 



30-7 



36-2 



42-9 



44-8 



510 



52-2 



50-7 



49-6 



43-7 



41-5 



30-9 



11 



36-3 



30-8 



360 



42- 1 



43-8 



50-3 



517 



500 



49-1 



43-7 



41-7 



310 



It should be remarked, that the changes of temperature l>etween ll h 10 m p.m., and 12 h 10 m a.m., are 

 slightly inaccurate in Table II.; this is due to the variations of temperature between ll n 10 m p.m. of the 

 Saturdays, and 12 h 10 m a.m. of the Mondays, and to the difference between the temperature at 12 h 10 m a.m., 

 the first hour of the month, — and ll h 10 m p.m., the last hour. The changes of temperature between 11 h 10 m 

 p.m., and 12 h 10 m a.m., as determined by the observations for each month, where the interval was only one 

 hour, are as follow, namely, temperature at 12" 10 m a.m., minus temperature at ll h 10 m p.m.: — 



Jan. Feb. March. April. May. June. July. 



0°.Q0 -0°-15 -0°-20 -0°-24 -0°-85 -0°-39 -0°-77 



Aug. Sept. Oct. Nov. Dec. Year. 



-0°-33 -0°-47 -0°-36 + 0°18 + 0°-05 -0°-30 



The changes actually exhibited in Table II. are — 

 _0°-9 -0°-9 -0°-7 -0°-l -1°-1 -0°-7 -1°'3 



0°-0 -0°-6 



■0°-8 +0°-l +0°-4 -0°-55 



Diurnal Variation of Temperature. — When the true changes of temperature at midnight are remembered, 

 it will be seen that in the three months of November, December, and January, the temperature varies little 

 more than 0°-5 for five or six hours before and after midnight ; the minimum in these months, therefore, is not 

 very distinctly marked. The following are the approximate epochs for each month of 1844 : — 



Jan. Feb. March. April. May. June. July. Aug. Sept. Oct. Nov. Dec. 



Min. a.m. 5 h 10 m 2 h — 4 h 6 h 10™ 4 h 30 m 3 h 40™ 3 h 10 m 3 h 30™ 4 h 30 m 4 h 30 m 5 h 10 m 10 h — 4 h 10 h — 9 h 

 Max. p.m. l h 30 m l h 40 m 2 h 20 m 2 h 10 m 2 h 10 m l h 10 m 3 h 10 m l h 30 m l h 30 m 2 h 0™ l h 20 m l h 20 m 



The following Table contains the means for the astronomical quarters (November, December, and January 

 being winter), and for the year. 





