Pressure of Aqueous Vapour. 



415 



The pressure is constant in the winter quarter from 7 h p.m. till 6 h a.m. ; and in the mean for the year the 

 pressure is nearly constant from ll h a.m. till 3 h p.m. 



The mean tension of aqueous vapour for the year occurs at 7 h 50 m a.m. 

 8 h 30 m p.m. 



The interval between the two epochs of mean tension is 12 h 40 m 



TABLE XII. — Hourly Means of the Pressure of Aqueous Vapour for each Month in 1844, 



as deduced from Tables II. and VIII. 



Mak. 

 M. T. 



Jan. 



Feb. 



March, t 



Lpril. 



May. .] 



fune. i 



ruly. 



\ug. 



Sept. 



Oct. 



Nov. 



Dec. 



h. 



in. 



in. 



in. 



in. 



in. 



in. 



in. 



ill. 



in. 



in. 



in. 



in. 



12 



0-202 



0-167 



0-197 



•250 



•263 



•335 



■347 



340 



•332 



•263 



0-252 



185 



13 



•202 



•167 



•197 



251 



•258 



■330 



•344 



■336 



■327 



263 



•251 



184 



14 



•201 



•167 



•199 



243 



253 



•330 



■340 



332 



322 



259 



•253 



184 



15 



•204 



• 169 



•196 



238 



249 



•330 



•338 



328 



•319 



259 



•252 



182 



16 



•204 



•169 



•193 



239 



249 



327 



337 



326 



314 



258 



•252 



183 



17 



•204 



•172 



•193 



240 



254 



333 



345 



326 



313 



252 



•251 



183 



18 



•206 



•170 



•191 



245 



262 



344 



359 



336 



318 



255 



•253 



183 



19 



•208 



• 169 



•202 



258 



270 



348 



370 



351 



340 



256 



•253 



182 



20 



•213 



•174 



•208 



266 



279 



353 



370 



364 



355 



268 



•254 



181 



21 



•217 



• 181 



•210 



271 



279 



355 



372 



368 



365 



278 



•259 



181 



22 



•217 



•184 



•216 



278 



284 



364 



374 



370 



374 



286 



•262 



187 



23 



•224 



•186 



•216 



282 



285 



373 



376 



370 



374 



292 



•264 



190 







•227 



• 187 



•220 



280 



284 



383 



382 



366 



365 



291 



•261 



194 



1 



•232 



•186 



•216 



278 



283 



380 



381 



368 



362 



293 



•263 



196 



2 



•229 



•188 



•217 



275 



290 



373 



387 



371 



367 



290 



■259 



195 



3 



•226 



•186 



•216 ■ 



268 



291 



373 • 



384 



378 



369 



287 



•258 



191 



4 



•218 



•183 



•213 



268 



286 



368 



377 • 



373 



366 



285 



•255 



187 



5 



•215 



•184 



•212 



265 ■ 



286 



369 



382 



369 



366 



280 



•251 



183 



6 



•210 



•179 



•208 



256 



283 



368 



372 



375 



361 



276 



•252 



182 



7 



•209 



•178 



•209 



253 



280 



359 • 



375 



368 



359 • 



277 



•252 



182 



8 



•208 



•178 



•207 



249 



281 



351 



373 



370 



353 



271 



•251 



181 



9 



•209 



•173 



•203 



249 



276 • 



347 ■ 



365 • 



354 



348 • 



268 



•250 



181 



10 



•207 



•174 



•204 



246 



271 



343 | ■ 



361 



349 



340 ■ 



266 



•249 • 



182 



" 



•209 



• 174 



•203 • 



249 



267 



339 



357 



333 



337 • 



266 



•249 



181 



TABLE XIII. — Hourly Means of the Pressure of Aqueous Vapour for each Astronomical Quarter, 



and for the Year 1844. 



Mak. 

 M T 



Nov. 

 Dec. 



Feb. 

 March 



May 

 June 



Aug. 

 Sept. 



Year 

 1844 



Mak. 

 M T 



Nov. 

 Dec. 



Feb. 

 March 



May 

 June 



Aug. 

 Sept. 



Year 

 1844. 





Jan. 



April. 



July. 



Oct. 







Jan. 



April. 



July. 



Oct. 



h. 



in. 



in. 



in. 



in. 



in. 



h. 



in. 



in. 



in. 



in. 



in. 



12 



0-213 



0-205 



0-315 



0-312 



0-261 







0-227 



0-229 



0-350 



0-341 



0-287 



13 



•212 



•205 



•311 



•309 



•259 



1 



•230 



•227 



•348 



•341 



•287 



14 



•213 



•203 



•308 



•304 



•257 



2 



•228 



•227 



■350 



•343 



•287 



15 



•213 



•201 



•306 



•302 



•255 



3 



•225 



•223 



•349 



•345 



•286 



16 



•213 



•200 



•304 



•299 



•254 



4 



•220 



•221 



•344 



•341 



•282 



17 



•213 



•202 



•311 



•297 



•255 



5 



•216 



•220 



•346 



•338 



•280 



18 



•214 



•202 



•322 



•303 



•260 



6 



•215 



•214 



•341 



•337 



•277 



19 



•214 



•210 



•329 



•316 



•267 



7 



•214 



•213 



•338 



•335 



•275 



20 



•216 



•216 



•334 



•329 



•274 



8 



•213 



•211 



• 335 



•331 



•273 



21 



•219 



•221 



•335 



•337 



•278 



9 



•213 



•208 



•329 



•323 



•269 



22 



•222 



•226 



•341 



•343 



•283 



10 



•213 



•208 



•325 



•318 



•266 



23 



•226 



•228 



•345 



•345 



•286 



11 



•213 



•209 



•321 



•312 



•264 



