1. I have already, in communications to the Society, urged the importance which belongs to simultaneous tide observations made at distant places; and I have also stated some of the steps which have been taken in consequence of representations to this effect. Observations were made and continued for a fortnight in June 1834, at the coast-guard stations in Great Britain and Ireland; and I have given an account of some of the results of these observations in a paper already printed in the Transactions. Being encouraged by the general interest taken in the subject, and by the desire to promote this branch of knowledge manifested by those who had officially the means of doing so, especially by Captain Beaufort, the Hydrographer of the Admiralty, I solicited a repetition of the coast-guard tide observations in June 1835, and also ventured to recommend that a request should be made to other maritime nations, to institute simultaneous tide observations on their coasts. The British observations were undertaken with the same readiness as before by Captain Bowles, the Chief Commissioner of the Coast-Guard Service. The proposal for the foreign observations was entertained and promoted with great zeal by the Board of Admiralty; and the Duke of Wellington, at that time Foreign Secretary of State, being applied to, to forward the scheme, His Grace fully acceded to the application, and made requests to foreign governments to join in the undertaking, in a manner which procured from them the most cordial and effective cooperation. Through the ambassadors of the maritime powers of Europe, and through A. Vail, Esq., the Chargé d’Affaires of the United States, who entered into this design with great interest, arrangements were made, and directions circulated, for simultaneous tide observations from the 8th to the 28th of June. These observations were made, for the most part with great care, under the direction of intelligent officers and men of science. 2. The chain of places of observation extended from the mouth of the Mississippi, round the Keys of Florida, along the coast of North America, as far as Nova Scotia; and from the Straits of Gibraltar, along the shores of Europe, to the North Cape of Norway. The number of places of observation was twenty eight in America, seven in Spain, seven in Portugal, sixteen in France, five in Belgium, eighteen in the Netherlands, twenty-four in Denmark, and twenty-four in Norway; and observations were made by the coast-guard of this country at 318 places in England and Scotland, and at 219 places in Ireland. Among the persons who superintended these observations on an extensive scale, I have profited in an especial manner by the labours of M. Möll, who directed and arranged those made in the Netherlands; M. Tegner, who has performed various reductions on the Danish observations, besides superintending a large portion of them; and M. Beautems-Beaupre, who has for some years been occupied with valuable hydrographical labours on the coasts of France. In several other cases in which the observations have been conducted in a very accurate and scientific manner, I do not find it stated, in the communications which contain the registers, under whose general direction the operations were carried on. The names of the particular observers will be found in the Tables appended to this memoir. I have not used the whole of the observations sent; as some, from the situation of the places, or from other causes, could not be made subservient to my general purpose. For instance, I have for the present omitted some, on account of their manifestly irregular character; others, because, being made at some distance up the course of a river, they gave no information respecting the tides of the ocean. Such data as these last mentioned may still be of use to myself or other investigators on some future occasion.
XVII. Researches on the tides.—Sixth series. On the results of an extensive system of tide observations made on the coasts of Europe and America in June 1835
