XXIX. On the tides of Bombay and Kurrachee

Abstract

The tides on the coasts of India present a marked difference from those on our own coasts in the large amount of diurnal inequality to which they are subject. My attention was first directed to the subject in the course of an engineering survey of the Harbour of Kurrachee which I made in 1857-58, when I obtained between three and four months’ continuous observations, a copy of which is deposited with the Royal Society. Subsequently I obtained from the Admiralty, through the kindness of Captain Burdwood, R. N., the loan of the records of three years’ observations taken at Bombay in 1846, 1847, and 1848. Of these I plotted in a series of continuous curves the records for 1846, and deposited them, at the Astronomer Royal’s request, at the Royal Observatory, Greenwich. These records, however, are not perfect. They were made by a self-acting machine, the adjustment of which does not appear to have been always accurately pre­served; and I hope that they will be superseded as data for investigation by a better record 'for the year 1868. Taking them as they were, however, I discussed them to obtain the semimonthly curves of semidiurnal tide, and also formulæ for the approxi­mate determination of diurnal tide.