Weather Warnings for Watchers - Anonymous

[12]. The Aneroid Barometer: How to Buy and How to Use it. By a Fellow of the Meteorological Society. Post free for six stamps, from any bookseller or optician.

The height of mountains may also be determined by the temperature at which water boils, as this depends on the pressure of the atmosphere, and according to Deschanel, “just as we can determine the boiling-point of water when the external pressure is given, so if the boiling-point be known we can determine the external pressure,” and as this varies with the elevation above sea-level, the boiling-point of water also varies.

These facts induced Wollaston to attempt the determination of heights of mountains by an apparatus which he called the Barometric Thermometer, subsequently modified by Regnault and called a Hypsometer, but now more generally known as a Boiling-point Thermometer.

33.
Boiling-point
Thermometer.
Scale about 1/3.

A portable form of boiling-point thermometer is shown at Fig. 33, which is much used by Alpine travellers, and forms a trustworthy check on the aneroid and barometer.

Concise Tables for calculating heights by means of Barometer orAneroid, and also by the Boiling-point Thermometer.
Boiling-point of Water for pressure in next col.	Barometer at lower Station.	BAROMETER AT UPPER STATION.—INCHES.
Boiling-point of Water for pressure in next col.	In.	30	29	28	27	26	25	24	23	22	21	20	19	18	17	16	15
213·78	31	859	873	889	905	921	939	957	977	998	1020	1043	1068	1095	1124	1155	1188
212·13	30	....	888	904	920	937	955	974	994	1015	1038	1062	1087	1115	1144	1176	1210
210·43	29	....	....	919	936	953	971	991	1012	1033	1056	1081	1107	1135	1165	1198	1233
208·67	28	....	....	....	952	970	989	1009	1028	1051	1075	1100	1127	1156	1187	1220	1257
206·87	27	Factor A.				988	1007	1028	1050	1073	1097	1122	1150	1180	1211	1246	1283
205·01	26	....	....	....	....	....	1027	1048	1070	1093	1118	1145	1173	1203	1236	1271	1309
203·09	25	....	....	....	....	....	....	1069	1092	1116	1141	1169	1198	1229	1262	1299	1338
201·11	24	....	....	....	....	....	....	....	1115	1140	1166	1194	1224	1256	1290	1327	1367
199·05	23	....	....	....	....	....	....	....	....	1164	1191	1220	1251	1284	1319	1358	1399
196·92	22	....	....	....	....	....	....	....	....	....	1218	1248	1280	1314	1350	1390	1433
194·71	21	....	....	....	....	....	....	....	....	....	....	1278	1310	1346	1383	1424	1469
192·41	20	....	....	....	....	....	....	....	....	....	....	....	1343	1380	1419	1461	1507
190·00	19	....	....	....	....	....	....	....	....	....	....	....	....	1416	1457	1500	1548
187·50	18	....	....	....	....	....	....	....	....	....	....	Factor A		....	1497	1542	1592
184·87	17	....	....	....	....	....	....	....	....	....	....	....	....	....	....	1588	1639
182·10	16	....	....	....	....	....	....	....	....	....	....	....	....	....	....	....	1690
179·20	15

Height in 1,000 feet.	Factor D. additive.	Latitude.	Factor C.	Mean Temperature.	Factor B.
2	5	0°	†2·7	10°	0·951
4	11	10	†2·5	20	0·973
6	17	20	†2·0	30	0·996
8	23	30	†1·4	40	1·018
10	30	40	†0·6	50	1·040
12	37	45	0·0	60	1·062
14	44	50	-0·5	70	1·084
16	52	60	-1·3	80	1·127
18	60	70	-2·0