in glass-making, a substance which serves to colour glass.

FERRÓ, or Hiero, the most westerly of the Canary Islands, and, besides being the smallest, also the most arid and barren. It has a population of about 5000 souls, and a superficies of twenty square miles. The coast is rugged, and the soil contiguous to it is barren; but in the interior face of the country improves, and there is a consider- able portion of the island level and fruitful. The chief product is figs, which are produced in great quantities; and, to prevent their being lost, they are frequently used in making brandy. This spirit, together with wine, which is also made here, is exported to Teneriffe. Various ar- omatic flowers grow in great abundance; and bees thrive exceedingly well, yielding excellent honey. Ferro is but scantily supplied with water, there being only two or three fountains on the island; so that the cattle, which are nume- rous, are but ill provided with this indispensable com- modity. Ferro was formerly supposed to be the most wester- ly point of the old world, and hence geographers drew their first meridian of longitude through it. This practice, how- ever, has been abandoned; and almost every nation now makes the first meridian to pass through its own capital, not, we apprehend, with any advantage to science, but ra- ther the reverse. Long. 17. 46. W. Lat. 27. 45. N.