VI. On the laws of individual tides at Southampton and at Ipswich

Abstract

With the view of verifying the reported peculiarity in the tides at Southampton, I had proposed in the month of February 1842 to proceed thither for the purpose of examining, with my own eyes, the rise and fall of the water during one or more tides. As soon, however, as my purpose was made known to Colonel Colby, R. E., Director of the Trigonometrical Survey, and to Lieutenant Yolland, R. E., the Resident Officer at the Ordnance Map Office, Southampton, I received from those gentlemen the offer of placing at my service, for these observations, non-commissioned officers and privates of the corps of Royal Sappers and Miners, as well as of preparing and fixing the vertical scale of feet and inches, and of keeping a watch upon the general accuracy of the observed times. I was extremely glad to avail myself of this offer, for I believe that a more intelligent and faithful body of men does not exist than the Sappers employed in the Trigonometrical Survey; and I knew well the advantage of employing, upon a tedious business like this, a set of regular-service men stationed on the spot. A vertical scale of deal laths, upon which the divisions and figures were branded, was fixed near the end of the pier at Southampton, very near to the landing-stairs on the north side of the pier, so that the divisions could at all stages of the tide (with the assistance of a lantern at night) be easily read by a person standing on the stairs. The order of the graduations of the scale was increasing from the bottom upwards, and the zero of the scale was found, by levelling, to bear the following relation to cer­tain fixed marks:—