As by a famous experiment of Mr. Boyles it appears that ice evaporates very fast in severe frosty weather when the wind blows upon it; and as ice in a thawing state is known to contain six times more cold than water at the same degree of sensible coldness, it is easy to understand that winds blowing over islands and continents of ice perhaps much below nothing on Farenheit's scale, and coming from thence into our latitude must bring great degrees of cold along with them. If we add to this the quantity of cold produced by the evaporation of the water as well as by the solution of the ice, we cannot doubt but that the northern ice is the principle source of the coldness of our winters, and that it is brought hither by the regions of air blowing from the north, and which take an apparent easterly direction by their coming to a part of the surface of the earth which moves faster than the latitude they come from. Hence the increase of the ice in the polar regions by increasing the cold of our climate adds at the same time to the bulk of the Glaciers of Italy and Switzerland. If the nations who inhabit this hemisphere of the globe, instead of destroying their sea-men and exhausting their wealth in unnecessary wars, could be induced to unite their labours to navigate these immense masses of ice into the more southern oceans, two great advantages would result to mankind, the tropic countries would be much cooled by their solution, and our winters in this latitude would be rendered much milder for perhaps a century or two, till the masses of ice became again enormous. Mr. Bradley describes the cold winds and wet weather which sometimes happen in May and June to the solution of ice-islands accidentally floating from the north. Treatise on Husbandry and Gardening, Vol. II. p. 437. And adds, that Mr. Barham about the year 1718, in his voyage from Jamaica to England in the beginning of June, met with ice-islands coming from the north, which were surrounded with so great a fog that the ship was in danger of striking upon them, and that one of them measured fifty miles in length. We have lately experienced an instance of ice-islands brought from the Southern polar regions, on which the Guardian struck at the beginning of her passage from the Cape of Good Hope towards Botany Bay, on December 22, 1789. These islands were involved in mist, were about one hundred and fifty fathoms long, and about fifty fathoms above the surface of the water. A part from the top of one of them broke off and fell into the sea, causing an extraordinary commotion in the water and a thick smoke all round it.] [_Threefold train_. l. 539. The river Niger after traversing an immense tract of populous country is supposed to divide itself into three other great rivers. The Rio Grande, the Gambia, and the Senegal. Gold-dust is obtained from the sands of these rivers.]