# Transactions of the Geological Society, 1st series, vol. 4/Barometrical Measurements

 Barometrical Measurements

XIX. Barometrical Measurements.

By WILLIAM ALLEN, F.R.S

member of the geological society.

[Read 19th November, 1812.]

The following measurements were made with a single Barometer of the construction proposed by Sir Henry Englefield, and have been calculated according to the formula recommended by him in his memoir on the subject, which is inserted in the 14th volume of Nicholson's Journal. I shall give in detail the observations made upon Snowdon; and of the other measurements I shall mention only the results.

 Snowdon. Observ. Hour September 8th, 1806 Therm. Barom. 1 A.M. 9 00 Goat Inn, Beddgelert 61 29.69 2 —— 10 25 Llyn Cader 61 29.162 3 P.M. 1 25 Summit of Snowdon 50 26.164 4 —— 4 00 Llyn Cwellyn 56 29.30 5 —— 4 45 Llyn Cader 57 29.12 6 —— 6 00 High water-mark at Pont-aber-glas-Llyn 55 29.78 7 —— 6 30 Goat Inn at Beddgelert 53 29.6

It appears from observations 1 & 7 that the Barometer had fallen at Beddgelert in 9$\scriptstyle \frac 12$ hours 0.09 inches, and from observations 2 & 5 that it had fallen at Llyn Cader in 6$\scriptstyle \frac 14$ hours 0.042 inches. The descent of the mercury may therefore be estimated at about 0.008 inches an hour, for which due correction has been made in each observation on calculating the measurements.

 Feet. From Observations 6 and 7, the height of Beddgelert Inn above high water-mark = 162.7 From Observations 1 & 4, the height of Llyn Cwellyn above Beddgelert = 314.2 above the Sea = 476.9

 From Obs. 1 & 2 From Obs. 1 & 3 mean The height of Llyn Cader above Beddgelert 489.3 480.2 484.7 above the Sea 652. 642.9 647.4 From Obs. 1 & 3 From Obs. 3 & 7 mean The height of Snowdon above Beddgelert 3457.5 3409. 3433.2 above the Sea 3620.2 3571.7 3595.9

In the following measurements only one observation was made at the lower station, unless the contrary is stated.

The height of the highest Peak above Dollgellau 2879
The height of the highest of the three Heads above Dollgellau 2840
Ingleborough
The height of Ingleborough above the Bay-horse Inn, Ingleton 1881
Ingleton is 90 feet below Settle; the height of Settle has been accurately taken, and is stated at 621 above the sea; therefore the height of Ingleton above the sea is 531
and the height of Ingleborough above the sea is 2412
Whernside
The height of Whernside above Ingleton 1930
above the sea 2461
Pen-y gant.
The height of Pen-y gant above Settle 1858
above the sea 2479
Shap Fells.
The height of the highest point in the road between Kendal and Shap above Kendal 1187

Helvellyn.
From two observations made the same day at Paterdale.—Day rainy.-The Barometer varied .194 in 5 hours.—The Inn at Paterdale is 24 feet above Ullswater.
The height of Grisdale brow above Ullswater 988
──── of RedTarn 1935
──── of the top of Helvellyn 2686
Threlkeld, where the first observation was made, is 235 feet above the level of Keswick Lake, which is 228 feet above the sea.
 above Keswick Lake. above the Sea The height of Saddleback—the Pummel 2615 2843 the Crupper 2561 2789
Skiddaw.
The Oak Inn at Keswick, where the first observation was made, is 28 feet above the lake, which is 228 feet above the sea.
 above Keswick Lake. above the Sea The height of Latrigg 330 558 of Half-way stone 1408 1636 of the summit of Skiddaw 2789 3017
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XIX. Barometrical Measurements.

By SAMUEL WOODS, Esq.

member of the geological society.

[Read 19th November, 1812.]

In the following measurements only one observation was made at the lower station, unless the contrary is stated. They are calculated according to the formula of Sir Henry Englefield.