[58] Tacitus, after having given the report of the Britons as he had heard it, probably from Agricola, now goes on to state his own views on the subject. He represents that, as the far north is level, there is nothing, when the sun is in the distant horizon, to throw up a shadow towards the sky: that the light, indeed, is intercepted from the surface of the earth itself, and so there is darkness upon it; but that the sky above is still clear and bright from its rays. And hence he supposes that the brightness of the upper regions neutralizes the darkness on the earth, forming a degree of light equivalent to the evening twilight or the morning dawn, or, indeed, rendering it next to impossible to decide when the evening closes and the morning begins. Compare the following account, taken from a "Description of a Visit to Shetland," in vol. viii. of Chambers' Miscellany:--"Being now in the 60th degree of north latitude, daylight could scarcely be said to have left us during the night, and at 2 o'clock in the morning, albeit the mist still hung about us, we could see as clearly as we can do in London, at about any hour in a November day." [59] Mr. Pennant has a pleasing remark concerning the soil and climate of our island, well agreeing with that of Tacitus:--"The climate of Great Britain is above all others productive of the greatest variety and abundance of wholesome vegetables, which, to crown our happiness, are almost equally diffused through all its parts: this general fertility is owing to those clouded skies, which foreigners mistakenly urge as a reproach on our country: but let us cheerfully endure a temporary gloom, which clothes not only our meadows, but our hills, with the richest verdure."--Brit. Zool. 4to. i. 15. [60] Strabo (iv. 138) testifies the same. Cicero, on the other hand, asserts, that not a single grain of silver is found on this island. (Ep. ad Attic, iv. 16.) If we have recourse to modern authorities, we find Camden mentioning gold and silver mines in Cumberland, silver in Flintshire, and gold in Scotland. Dr. Borlase (Hist. of Cornwall, p. 214) relates, that so late as the year 1753, several pieces of gold were found in what the miners call stream tin; and silver is now got in considerable quantity from several of our lead ores. A curious paper, concerning the Gold Mines of Scotland, is given by Mr. Pennant in Append. (No. x.) to his second part of a "Tour in Scotland in 1772," and a much more general account of the mines and ores of Great Britain in early times, in his "Tour in Wales of 1773," pp. 51-66.