The centre island has been only partially excavated, but the works there have been discontinued. At present it is entirely uninhabited, though there are still visible on its summit a few wooden huts, which formerly sheltered the workmen, as also some of the "shoots" or slides used for facilitating the collection and shipment of the guano.
The southernmost of the three islands is quite in its primitive state, never having been touched. No sign indicative of man's presence on it is anywhere visible.
The earliest attempts to export guano to Europe as a manure were made in 1832, but they proved so losing a speculation, that not till eight years later did the Peruvian mercantile house of Messrs. Quiros again direct attention to the importance of guano as an article of export, when the Government of Peru granted them, for a fixed sum, the exclusive privilege of exporting guano for six years. This gave an opportunity for instituting, on a sufficient scale, those experiments which, it will be remembered, Mr. Meyer of Liverpool was making at that period, and which was followed by such surprising results.
From March to October, 1841, 23 vessels conveyed 6125 tons of guano to England, Hamburg, Antwerp, and Bordeaux. In November of the same year, the English barque _Byron_ brought to Peru the cheering intelligence that a ton of guano was selling in England for £28 per ton. This totally unexpected and startling result induced the Government, by a decree of 17th November, to declare that the agreement with Messrs. Quiros was cancelled, and fresh offers for the privilege of shipping guano were invited from speculators.
Since that period the exportation of this important manure has attained unprecedented dimensions in every part of the globe. Of late years it has reached the enormous amount of 500,000 tons from these islands alone, and the revenue to the Government has been 12,000,000 to 15,000,000 dollars.
The contractors sell the guano in Europe for account of the Peruvian Government, and receive for it a commission fee of from 3-1/2 to 4-1/2 per cent. of the gross amount; for this they get, moreover, paid 5 per cent. of interest for outlays and pecuniary advances (pretty considerable) which they make to the native Government. The contracts are generally entered into for four years.