418 JOURNAL OF THE PLYMOUTH INSTITUTION. 
TIDAL AND GENEEAL NOTES ON CATTEWATER. 
BY R. N. WORTH, F.G.S. 
(Read at the Anniversary Meeting, May, 1886.) 
I am indebted to Major Daubeny for the opportunity of examining 
an interesting MS. written in 1839 by a certain " J. B.," then 
residing at Stonehouse, and who from internal evidence as well as 
external was Mr. Blackburne, for some years lessee of the dock at 
Turnchapel, and the author of certain plans for the improvement 
of Sutton Pool, referred to in Burt's Commerce of Plymouth. 
Some of the notes contained in this MS. are of considerable value, 
especially those upon the tides at Plymouth, based upon a series 
of observations "carefully" made "and registered at Turnchapel 
in the harbour of Catwater during the several years of 1803, 1804, 
and 1805. This was about nine years before the first stone of the 
Breakwater in Plymouth Sound was deposited." The important por- 
tions of these observations are embodied in the following extracts : 
"The two spring tides of each lunation flow to an unequal 
height, or one rises higher than the other, and there is a periodical 
alteration of when the highest of these two spring tides takes 
place. At one time of the year the full moon spring tides are 
higher than those of the new moon. At another time of the 
year the new moon spring tides- are higher than those of the full 
moon. This alteration takes place at the winter and summer 
solstices. From January to July the new moon spring tide is the 
highest, and from July to January the full moon spring tide is 
the highest. The best spring tide rises 9 inches higher than the 
other, and falls 13 inches lower than the other. There is also a 
difference in the height of the rise of the tides in the morning 
and evening, and there is also a periodical alteration in this respect, 
which takes place at the spring and autumnal equinoxes. The 
morning tides are higher than the evening tides between September 
and March, and the evening tides are the highest between March 
and September. The tides are fifteen minutes longer in falling 
than in flowing. 
"A north-east wind occasions the least rise and the lowest fall 
