Table IV. is to correct for the diminution of gravity in ascending from the sea-level.

To use these Tables: The barometer readings at the upper and lower stations having been corrected and reduced to temperature 32° F., take out from Table I. the numbers opposite the corrected readings, and subtract the lower from the upper. Multiply this difference successively by the factors found in Tables II. and III. The factor from Table III. may be neglected unless precision is desired. Finally, add the correction taken from Table IV.

Table I.

Approximate Height due to Barometric Pressure.

Inches.Feet.Inches.Feet.Inches.Feet.
31·0028·2247525·45209
30·984·12568·35312
·816928·02661·25415
·725427·92754·15519
·6339·8284825·05623
·5425·7294224·95728
·4511·63037·85833
·3597·53132·75939
·2683·43227·66045
·1770·33323·56152
30·0857·23419·46259
29·9944·13515·36366
·8103227·03612·26474
·7112026·93709·16582
·61208·8380624·06691
·51296·7390423·96800
·41385·64002·86910
·31474·54100·77020
·21563·44199·67131
·11653·34298·57242
29·01743·24398·47353
28·91833·14498·37465
·8192426·04598·27577
·7201525·94699·17690
·62106·8480023·07803
·52198·7490222·97917
·42290·65004·88032
·32382·55106·78147

Table I.—continued.

Approximate Height due to Barometric Pressure.

Inches.Feet.Inches.Feet.Inches.Feet.
22·6826218·91293715·218632
·58378·813076·118805
·48495·71321515·018979
·38612·61335514·919154
·28729·513496·819330
·18847·413638·719507
22·08966·313780·619685
21·99085·213923·519865
·89205·114067·420046
·7932518·014212·320228
·6944617·914358·220412
·59567·814505·120597
·49689·71465214·020783
·39811·61480013·920970
·29934·514949·821159
·110058·415099·721349
21·010182·315250·621541
20·910307·215402·521734
·810432·115554·421928
·71055817·015707·322124
·61068416·915861·222321
·510812·816016·122520
·410940·71617213·022720
·311069·61632912·922922
·211198·516487·823126
·111328·416646·723331
20·011458·316806·623538
19·911589·216967·523746
·811721·117129·423956
·71185316·017292·324168
·61198615·917456·224381
·512120·817621·124596
·412254·71778712·024813
·312389·61795411·925032
·212525·518122·825253
·112662·418291·725476
19·012799·318461·625700