420 



Results of Makerstoun Observations, 1844. 



Annual Variation of Atmospheric Pressure. — In 1844, the monthly mean of the height of the barometer 

 was lowest in February, being 29-321 in. ; and it was highest in May, being 29-980 in. : the range of the 

 monthly means, therefoi*e, was 0-659 in. The following are the mean pressures, in inches, of mercury at 32 D 

 for each of the meteorological quarters of 1844 : — 



Winter, Dec, Jan., Feb., 29-635 



Spring March, April, May, 29-771 



Summer, June, July, Aug., 29580 



Autumn, Sept., Oct., Nov., 29-592 



The mean pressure for the year 1844, = 29-645. 



The pressure of the atmosphere was least in summer, and greatest in spring. The three consecutive 

 months with the lowest mean pressure, are January, February, and March, the mean being 29-514 in. ; and 

 the three with the highest mean pressure are April, May, and June, the mean being = 29-804 in. 



TABLE XIX. — Diurnal Range of the Barometer for each Civil Day, with the Weekly and Monthly 



Means, for 1844. 



Civil 

 Day. 



an. 



Feb. W 



arch. 1 



^pril. ] 



Hay. 



une. < 



fuly. 



Ug. i 



Sept. 



Oct. ] 



Sov. ] 



3ec. 





in. 



in. 



in. 



in 



in. 



in. 



in. 



in. 



in. 



in. 



in. 



in. 



1 0- 



Ill 



0-320 



200 



098 



070 



082 



042 



163 [0 



074] 



209 



134 [0 



163] 



2 



392 



•449 



106 



407 



130 [ 



107] 



031 



107 



064 



382 



124 



158 



3 



226 



•199 [ • 



272] 



070 



130 



063 



062 



296 



037 



255 [ 



160] 



262 



4 



211 



[ -257] 



460 



077 



081 



141 



090 [ 



256] • 



070 



187 



315 



118 



5 



461 



•063 



052 



228 [ 



144] 



254 



044 



095 



179 



182 



128 



059 



6 



268 



•161 



361 



260 



258 



098 



209 



653 



168 [ 



297] • 



156 



068 



7 [ 



330] 



•349 



139 [ • 



202] 



183 



159 [ 



133] 



224 



058 



220 



090 



088 



8 



535 



•053 



498 



169 



081 



327 



111 



210 [ 



143] 



501 



421 [ 



120] 



9 



259 



•555 



420 



055 



083 [ 



187] • 



099 



165 



112 



438 



106 



138 



10 



246 



•308 [ 



363] 



421 



138 



161 



244 



113 



262 



390 [ 



217] 



168 



11 



113 



[ -216] 



355 



160 



117 



099 



061 [ 



172] 



080 



286 



178 



199 



12 



206 



•098 



659 



345 [ 



117] 



276 



127 



139 



214 



269 



156 



160 



13 



219 



•072 



110 



074 



077 



166 



654 



228 



058 [ 



235] 



350 



226 



14 [ 



137] 



•213 



269 [ 



179] 



164 



184 [ 



218] 



180 



185 



181 



463 



069 



15 



106 



•296 



172 



176 



126 



271 



161 



331 [ 



169] 



054 



417 [ 



197] 



16 



099 



•048 



466 



149 



371 [ 



182] 



127 



240 



141 



230 



270 



100 



17 



082 



•140 [ 



341] 



170 



137 



242 



181 



358 



227 



345 [ 



•303] 



100 



18 



333 



[ -223] 



119 



252 



200 



122 



121 [ 



243] 



191 



256 



131 



525 



19 



189 



•478 



518 



059 [ 



173] 



108 



247 



312 



043 



395 



147 



366 



20 



133 



• 174 



505 



061 



091 



195 



242 



143 



100 [ 



255] 



393 



082 



21 [ 



•153] 



•203 



293 [ 



• 214] 



201 



103 [ 



150] 



072 



045 



433 



112 



041 



22 



•125 



•199 



269 



105 



040 



136 



068 



089 [ 



084] 



065 



173 [ 



•109] 



23 



•105 



•738 



134 



396 



090 [ 



125] 



125 



131 



150 



037 



077 



036 



24 



•036 



•706 [ 



321] 



•409 



101 



096 



098 



142 



•134 



116 [ 



•111] 



.032 



25 



•297 



[ -403] 



324 



123 



134 



104 



078 [ 



•097] 



031 



097 



125 



097 



26 



082 



•546 



416 



•198 [ 



096] 



118 



191 



077 



071 



■241 



■056 



166 



27 



•263 



• 119 



489 



■171 



041 



047 



059 



085 



111 [ 



•151] 



■125 



043 



28 [• 



266] 



•112 



267 [ 



•124] 



176 



115 [ 



■179] 



060 



193 



• 107 



•121 



181 



29 



438 



•455 



061 



•075 



■034 



■045 



043 



076 [ 



•231] 



•236 



•242 [ 



•122] 



30 



195 





•093 



•106 



•055 [ 



•057] 



•540 



097 



•419 



• 112 



•075 



143 



31 



■323 



[ 



•166] 





•050 





•164 



• 102 





• 103 





146 



Mean 



•224 



0-282 



•298 



•185 



•124 



•148 



•156 



• 181 



•134 



•234 



•196 



145 



Annual Variation of the Mean Diurnal Ranges of Atmospheric Pressure. — The mean of the diurnal ranges 

 is greatest for the month of March, being 0-298 in. ; and it is least for the month of May, being 0-124 in. The 

 annual variation of the diurnal ranges, is exactly the reverse of the annual variation of the pressures ; when 



