This historic book may have numerous typos and missing text. Purchasers can usually download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1889 edition. Excerpt: .out by Captain Oldham, in connection with the north and south declination of the moon. Equally clearly appears the occurrence of springs at greatest declination, and not at new and full moon, so that at Hobart there is no " age of the tide;" and in connection with this the influence of perigee is shown in the higher tides at south decimation.

Captain Oldhams caution is very useful while looking at these diagrams that we must remember that we have here only one months observation. But it is not likely that a years observations will modify the above-mentioned facts. I believe they will be chiefly useful in showing that there is some regularity in the sequence and circumstances of the great apparent irregularities shown by these observations for one month. To show the nature and extent of these irregularities I have appended two diagrams showing for comparison a fortnights tide curves at Hobart and a fortnights at Bombay, and a diagram representing a normal curve of lunitidal intervals in contrast with the zig-zag mean line of such intervals at Hobart. These irregularities will, I think, show that no " establishment" that is--time of high water on the day of new or full moon--can be fixed, although on the months observations Captain Oldham mentions Sh, l m. At Hobart this is of no great consequence, as the depth of water in the harbour is such that the comparatively small rise and fall of tide does not much affect sailing arrangements. It is, however, very desirable that the observations to be taken should be as complete as those given by Captain Oldham, and I would press on the Society the desirability of co-operating with the Marine Board to secure this. The importance of the registration of the actual tidal action speaks for.