52 
Proceedings of the Royal Society 
Table VIII. — Variations in Density. 
Station. 
Maxi- 
[mum. 
Mini- 
mum. 
Mean. 
No. of 
Ohs. 
I. Alloa, .... 
1*00160 
0*99923 
1*00042 
4 
II. Kincardine, 
1*01521 
1*00070 
1*00680 
4 
III. Hen and Chickens Buoy, . 
1*02169 
1*01084 
1*01898 
11 
IV. Blackness, 
1*02414 
1*01650 
1*02087 
6 
V. Inchgarvie, 
1*02461 
1*01863 
1*02303* 
11 
VI. Oxcar, .... 
1*02492 
1*01953 
l*02355t 
10 
VII. Inchkeith,. 
1*02526 
1*02380 
1 *02472 
13 
VIII. . 
1*02544 
1*02450 
1*02505 
7 
IX 
1*02551 
1*02495 
1*02518 
8 
X. Off Fkldra, 
1*02557 
1*02417 
1*02530 
9 
XI. Off Bass Rock, . 
1*02566 
1*02526 
1*02547 
6 
XII May Island, . 
1*02570 
1*02443 
1*02511 
5 
Differences between Mean Densities in units of the fifth place. 
I. II. III. IV. V. VI. VII. VIII. IX. X. XI. XII. 
638, 1218, 189, 216, 52, 113, 33, 13, 12, 17 - 36. 
Note . — All the densities given are at 15° '56 C. 
An examination of Table VIII. shows that for maximum and 
minimum, as well as for mean observed densities, the increase is 
perfectly continuous until the last Station is reached, when the 
maximum density is only probably greater than that at Station XI., 
the minimum is certainly less than that at Station VIII., and the 
mean is less than that at Station IX. It is not easy to find an 
explanation of this fact, for there is no river nearer than the Tyne 
at Dunbar, and there are no springs on the Isle of May, the 
lighthouse keeper being compelled to get his fresh water all carried 
from Crail. It is, of course, possible that there may be some sub- 
marine springs near the island, but no indication of this is given by 
an examination of the bottom waters, which were always salter than 
* Omitting the day of high flood in the river mean = 1*02382. 
t „ „ ,, =1*02438. 
