458° H. A. Hazen—Reduction of Atr-pressure to Sea-level. 
TABLE II].—Mt. Washington above Portland, true difference 6240’, 
Laplace. | Diference || angot. | ,Piference || rrazen ci), | Difference 
nuary 6264’ +167 63297 +807 6245’ + 2! 
February 6268 +20 6299 +50 6242 — 1 
March 6284 +36 6306 +57 6265 +22 
April 6242 — 6 6244 — 5 6244 + 1 
May 6232 —16 6201 —48 6234 — 9 
June 6233 —15 6201 —48 6236 — 7 
July 6225 —23 6158 —91 6233 —10 
August 215 —33 6198 —51 6225 —18 
September} 6236 —12 6217 —32 6230 —13 
be 249 + J 6253 + 4 6246 + 3 
November} 6275 +27 6286 +37 6271 +28 
Decemb 6259 +11 6296 +47 6246 + 3 
Year 256 6267 6241 
Mean 42 mo’s 6248 6249 6243 
The following suggestion is made in the absence ef any 
all the observations for a series of years, at an 
other: Let 
elevated and at a lower neighboring station, be grouped as has 
already been proposed, then determine a formula which shall 
best represent all the observations, or, in other words, the laws 
Tasie IV. 
Law of variation of th 
Are 
of the pees 
term at different cc ae ae at Veldobbia and Great Lee Bernard 
| Temperature term variation for 
Pressure term variation for 
wee eapsrgneuosaiill 
each degree Centigrade. 
Pressure. Temperat’e, | 
Val. and Al, Ber. and Al. Val. and Al. 
55] 5™ 0°733™m ik — §°mm 071 8"™ 
552 “610 sas ae. 8 ‘15 
553, “500 pie | 0 90 
554 "633 eiec 3 23 
555 467 0°55™™ 6 23 
556 “67 63 9 “35 
557 *b4T "48 12 29 
558 *613 "62 15 ‘10 
559 “640 58 18 “12 
560 *590- “T6 21 -00 
561 “570 “65 
562 “640 *b8 
563 “650 "BT 
564 ‘570 “58 
565 “543 “66 
566 “603 “55 
567 547 “58 
568 “580 54 
569 503 “60 
570 “560 “65 
671 "590 “59 
572 “610 aay 
573 “BET ae he 
Mean “593 “598 
Ber. and Al. 
