454 ff. A. Hazen—Reduction of Air-pressure to Sea-level. 
high, situated in latitude 46° north, and seventy miles from 
Alessandria, in 45° north latitude and 318’ hi gh. 
Tasie I.—(In millimeters). 
-—6°C.| —8° 0° 3° 6° -. 12° 15° 18° 21° 
550 MPAALINIFAADLO FAT I1/(F°¥90-0 
(44 UltIGo J / tl tltod Oo] Le - one cece -<<ce ae ee 
SF A ew cea Tee 6 eal bcd pila ¢ 
555 |752°0|749°5| 746°6|745°2)|744°1/742°5| ___. a pipenpeene 
560 Sad ae ea eee » rrFO.T ee r40.0/F faa rin 4gOn 
v {Vi L todo!) 00'S) LoS LL) (OU UV! 140 6) 140 4) 144 6) ito VE a alse 
er PPO. K IRF RIT. A RP HN. PIM ZO. eee wera AIFF OLO MP CA-OIRP AAR 
565 |762°5|761°0)759°6| 758°1/ 755°3|754°4|752°3|750°3) 744°0: _ .- 
Fr RPOLAIFPO.LAI PRA PPO. Fear rrn rro Pr +, a a a aad 53 7 
570 |769°0|763-0| 764°8)763°0) T61°5| T59°0) 758° 1'T56°1)154"°6°7 03° 1 
In this table the first horizontal row of figures represents the 
mean temperature between the two stations, each vertical col- 
mn contains a mean of all the pressures observed at the 
lower station for 34 years at the time of the mean temperature 
at the head of the column, hence the column headed 0° con- 
tains a mean of all the pressures at ee ae between the 
mean temperatures of —1°5° C. and +i%5°C., distributed along 
the column according to the pressure at +s Valdobbia as indicated 
on the left, the original table runs to single millimeters. It 
will now be seen that we have the mean temperature between 
the two stations and the mean pressure at the upper and lower 
stations for a range of 27°C. of wes eee and 20mm. of 
pressure, from which we may compute, by Laplace, the differ- 
ence of elevation of the two stations, as in Table IL. 
LE I1.—(In meters). 
Elevation of Valdobbia above Alessandria. 
-6°C.| —3°. 0°. 3°. 6°. >. 12°. Be. 1 38°. Bie. 
551 | 2380! 2374] 2396] 2386] ._..| ....| .--.] -..-| --.-] ---- 
552 | 2376| 2376] 2376| 2390| 2396| ____| _...| _--.| _---] ---- 
553 | 2371) 237 
554 | 2379| 2374| 2381| 2388) 2391) ....| ....| --.-] -..-] ---- 
555 | 2385| 2378) 2370| 2382| 2397| 2405] ....| ...-| ..--] ---- 
556 | 2402| 2375| 2378) 2381| 2388] 2407| ....| ..-.| .---] ---- 
557 | 2368| 2375| 2374| 2396| 2399) 2411] 2392) ....| _.-.| ---- 
558 | 2362! 2379| 2383| 2379| 2396] 2396] _._.| _...] ... .| ---- 
559 | 2360] 2366] 2373| 2379| 2379] 2386) 2395| 2395] ____| ---- 
560 | 2356| 2369] 2377| 2383] 2388) 2395| 2399) 2411] 2419] -.. - 
561 | 2351| 2364| 2373| 2377| 2386] 2395) 2397, 2407| 2437] - -- - 
562 | 234%! 2370] 2376] 2376) 2382| 2398| 2393 2406] ___-| ---- 
563 | 2351| 2355| 2374| 2374! 2387| 2393] 2400) 2403] 2419] ---- 
564 | 23 
2 
565 | 2343) 2355| 2374] 2376] 2373) 2390) 2393) 2399] 2417) ---- 
566 | 2340} 2345| 2359] 2369] 2369) 2384| 2394! 2397| 2409) ---- 
567 | 2340] 2353] 2357| 2370) 2378) 2383| 2388) 2402) 2408; 2421 
568 | 2331) 2352] 2357} 2371) 2367| 2383) 2389) 2397) 2407) 2416 
569 | 2320} 2342] 2354! 2366) 2356) 2375; 2389) 2393) 2402) 2414 
570 | 2331 | 2316 235] (2358 2369 2368! 2385| 2391] 2399) 2412 
From this table it is evident that there is a great uniformity 
in the variation of the elevation as computed from Laplace. 
