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Other Inquiries concerning the Sea.
The Publisher of these Tracts knowing, that the Honorable Robert Boyle had not left unconsidered the Natural History of the Sea, of which Subject the late, and these present Papers, have entertained the Reader as to the Observables of its Flux and Reflux; He was, on this occasion, instant with that Gentleman to impart to him, for publication, these Heads of Inquiries, he had drawn up, touching that Subject: Which having obtained (though the Author desires, they may be lookt upon as unfinisht) he thus subjoyns.
What is the Proportion of Salt, that is in the Water of differing Seas; And whether in the same Sea it be always the same? And if it be not, how much it differs?
What is the Gravity of Sea-waters in reference to Fresh Waters and to one another: Whether it vary not in Summer and Winter, and on other Scores? And whether in the same Season its Gravity proceed only from the greater or lesser Proportion of Salt, that is in it, and not sometimes from other Causes? And what are the differing Gravities of the Sea-water, according to the Climats. *
* This last Clause containing a difficult Quære, and that may seem something odd, Mr. Boyle thinks fit to note, That having recommended this matter, among others, to a learned Physitian, that was sailing into America, and furnished him with a small Hydrostaticall Instrument, to observe from time to time the Differences of Gravity, he might meet with: This account was returned him, That he found by the Glass, the Sea-water to increase in weight, the nearer he came to the Line, till he arrived a certain Degree of Latitude; as he remembers, it was about the 30th, after which, the Water seemed to retain the same specifick gravity, till he came to the Barbados, or Jamaica.
What are the Odors, Colours and Tasts, observable in Sea-water?
What is the Depth of the Sea in several places, and the Order of its Increase and Decrements. And whether the Bottom of the Sea does always rise towards the Shore, unless accidentally interrupted?
Of the Bottom of the Sea, and how it differs from the Surface of the Earth, in reference to the Soyl, and Evenness or Roughness of the Superficies; And the Stones, Minerals, and Vegetables to be found there?
What the Figuration of the Seas from North to South, and from East to West, and in the several Hemispheres and Climats?
What communication there is of Seas by Streights, and Subterraneal Conveyances?
Of the Motion of the Sea by Winds, and how far Storms reach downwards towards the Bottom of the Sea?
Of the grand Motions of the Bulk or Body of the Sea; especially of the Tides: Their History as to their Nature and Differences.
