GB191002451A - Improvements in and relating to Tide Indicators. - Google Patents

Abstract

2451. Lenthall, C. B. Feb. 1. Calculating-apparatus. -Relates to means for calculating the height of the tide for any time at a place for which the height of the mean spring tide and the time of high water are known. A pivoted arm moves over a scale divided in one form into six hours and the quarters, or, as shown, into four, five, six, seven, or eight hours and quarters, and a scale A is fitted sliding parallel to the diameter of the circular scale and graduated to show height of tide. Setting is effected by bringing the half mean spring height of tide opposite the centre of rotation of the arm, and bringing a slider on the arm to the high-water for the day, the arm being coincident with the diameter. On moving the arm round through the interval that has elapsed since high-water, the reading on the scale A opposite the slider on the arm gives the required height. A simple slider may be employed as described above or, as shown, a pin on a nut L carried by a screwed arm N and adjusted by bevel gear from a milled head P may have a pin engaging a light sliding slotted plate J carrying the pointer H. The scale may be operated by means of a pinion. Instead of mechanical parts, suitable circles and lines may be employed as shown in Fig. 5.