A knowledge of the tides and currents has been principally acquired from the perusal of several works of the most renowned philosophers, whose erudition have stamped them with truth stable and incontrovertible. I have, therefore, adopted their language rather than my own, fearful I should mar their intent, and my regard for such comprehensive writings induces me to add the truism transmitted to us by an ancient Latin author— Unius ætatis sunt quæ fortiter fiunt, quæ Vero pro utilitate scribuntur æterna. _Vegetius_. Should the design be put in execution, and found efficacious, it will be applicable to other coasts, by taking every particular respecting them into consideration, and great will be the reward on the ambition attained of having endeavoured to benefit the community at large. THE AUTHOR. CHAPTER I. INTRODUCTION.—THE FORMATION OF THE TIDES CONSIDERED, THEIR VARIATION, AND EFFECTS. For, lo! the sea that fleets about the land, And like a girdle clips her solid waste, Music and measure both doth understand: For his great crystal eye is always cast Up to the moon, and on her fixed fast: And as she danceth in her pallid sphere, So danceth he about the centre here. The above lines, so beautifully expressed by one of our earlier poets, introduces a subject generally understood, but the important object connected with our present inquiry cannot be maintained without a thorough knowledge of cause and effect. A minute acquaintance, therefore, with the formation of the tides and currents, their variation and effects, transmitted to us by the observations, experiments, and discoveries of the earlier, and confirmed by the researches of the modern philosophers, will not be deemed altogether superfluous, as they will tend to remove any obstacle that might otherwise present itself on the consideration of so difficult a subject. By the term tide is meant that regular motion of the sea, according to which it ebbs and flows twice in the twenty-four hours.