Mr William Galbraith on the Tides and Dew-Point. 13 
wall, I chose a large stone exactly, by levelling, eight feet lower 
than the pier. I then determined, by a level, the height of the 
high water below the top of the pier, and the fall of the low water 
by a level and divided staff below the stone; whence, by adding 
8 feet, I got the measure of the low water below the pier. By 
this means I could get the number of feet and decimals the high 
and low water was each below the pier in the usual manner, as be- 
fore indicated by the divided rods, and the following table contains 
the results, though the mean Greenwich time cannot claim any very 
great precision. 
Remark.—Without precise operations of this kind, carefully exe- 
cuted, no confidence can be placed in the relative positions of land 
and water, or whether there be any gradual change of the land and 
sea levels so much insisted upon by popular writers, giving them- 
selves little trouble about the proper means of investigation. 
Register of the observed Heights of the Tides, as previously 
explained, under the top of Broddick Quay in 1849. 
Greenwi High Low Baro- hermo- 
RAPE: ori ame acter: meter. eae Weather. 
H. M. Feet. | Feet. | Inches. e 
Aug. 2,| 11°0 a.m. | 6°40 | 30°20 | 60 F. | Calm. 
2, 5°5 P.M. 12°60 | 30°20 | 60 ... Do. 
2,\11:20 em. | 5°67 30°20 | 60...| Do. 
3,| 5°25 a.m. 12°80 | 30°20 | GO... Do. 
3,| 11°40 a.m. | 6°41 30°20 | 60... Do. 
3,| 5°50 P.M. 13°00 | 30°20 | 60 ... Do. 
3,| 12°0 p.m. | 5°45 | 30°20 | 60 ... Do. 
4,| 6°20 a.m. 14°10 | 30°20 | GO ... Do. 
4,| 0°30 p.m. | 5°83 30°20 | 60... Do. 
4,| 6°45 p.m. | 13°00 30°10-| 61 ... Do. 
b; 10am. | 4°30 30°10 | 62 ... Do. 
5,| 7°10 p.m. 13:70 | 50°00 | 60... | Do. 
6,| 1:20 pm. | 4°70 30:00 | GO... Do. 
6,| 7°35 p.m. 13°00 | 30°00 | 60... Do. 
7,| 1°45 4m. | 4°50 50:00 | 60 ... Do. 
7,| 755 am. | ° 13°50 | 30°00 | 60... Do. 
Wo\ 2i0 pwr, | O20 30°00 | 60... Do. 
8,| 2°35 p.m. | 5°20 30°00 | 60 ... Do. 
9,| 3°10 p.m. 5°25 30°00 | 60... Do. 
10,| 9°45 a.m. 13°80 | 29°80 | 65 ... Do. 
10,| 3:55 pm. | 5°33 29°80 | 64 ... Do. 
12,| 5°35 pm. | 3°50 29°35 | 64 ... |Fresh Breeze. 
13,| 6:20 a.m. | 410 29925. \62\..5 Do. 
13,| 0°45 p.m. 12:00 | 29°20 | 62... Do. 
