Explorations were made for other deposits, and some rich ones were found on the Lobos Islands, off the north coast of Peru. A great many smaller islands were found to be covered with guano, and in various parts of the Pacific Ocean there are extensive deposits. The most important of these are upon Jarvis’s, Baker’s, and Howland’s Islands, situated in the South Pacific Ocean, belonging to a New York company, and named after American merchants interested in them. Jarvis’s Island was estimated a few years ago to contain nearly four millions of tons; the quantity on Baker’s and Howland’s Islands was not determined.
To show the rapid increase in the demand for guano, it may be mentioned that, in the year 1841, six thousand five hundred tons were exported from the Chincha Islands, and in the five following years, one hundred and twenty-seven thousand tons were exported,—or an average of more than thirty-five thousand tons a year.
In 1849 the exports of guano were nearly a hundred thousand tons, and from 1852 to 1857 the yearly average was more than two hundred thousand tons.
NATURE OF GUANO.
The value of guano varies according to the demand, but is ordinarily fixed at about seventy dollars a ton. It is sufficiently valuable to induce enterprising men to adulterate it; and more than half the guano sold in England and the United States is said to be mixed with inferior substances before it reaches the consumer. Nearly all dealers who purchase large quantities require a careful analysis of samples before they close their bargains. The analysis of guano is very desirable for the farmer, in order to indicate the best method of applying the fertilizer, and to ascertain for what crops and to what soils each kind is best adapted. For example, some soils might be most benefited by the Peruvian guano, which contains large quantities of ammonia; while others would be most benefited by the cheap qualities, which contain larger quantities of phosphate. Full details respecting the guano trade and the use of guano are contained in the document accompanying the message of the President of the United States to the Senate, February 5th, 1859.
Another locality where guano is found is in the Caribbean Sea, near the coast of Venezuela; but the islands containing this guano are in the region of tropical rains, and consequently the substance formed there is quite different in character from the dry, pulverized guano of the Chincha Islands. Some of these Caribbean islands are low, and covered with sand, shells, and other substances, in which the birds lay their eggs. Others rise in peaks to the height of several hundred feet; and on these peaks there are rocky layers which have been formed from guano. These rocky layers contain large quantities of phosphate and carbonate of lime. Other layers contain very little carbonate and a larger proportion of phosphate. Another variety is a solid rock, which forms a crust sometimes two feet thick, and consists mainly of phosphate and sulphate of lime. The evaporation of the ammonia and similar substances renders this rock porous, and has led many to believe that it was of volcanic origin. The heat and moisture of the surface have made wonderful changes in the organic substances or deposits of these islands; though the formation of these rocks can be directly traced to the excrement of birds and the remains of the birds themselves, all vestiges of animal life have disappeared, and the substance presents all the characteristics of a metamorphic rock, dug from the base of a volcanic mountain.
The work of handling guano is not the most delightful in the world; especially is this the case at Chincha Islands, where the air is dry, and the guano is in the form of dust, or of a hard material which easily separates into dust. Guano has a very pungent character, and causes the eyes to inflame, and sometimes deprives them altogether of the power of sight.
NORTH, SOUTH, AND MIDDLE ISLANDS.
As before stated, the Chincha Islands number three only, and are known as North Island, South Island, and Middle Island. The Middle Island is the most important, not only for having the largest quantity of guano upon it, but also for being the residence of the commander and deputy commander of the three islands. The palace of the commander is rather an imposing building of its character; and at a little distance stands that of the deputy commander. This is more modest and unpretending in architecture, being nothing more nor less than what Americans would term a flat-roofed shanty, constructed of cane and rush matting.
The average height of the rock which is the sub-strata of the island, is from one hundred and fifty to two and three hundred feet; and upon these rocks lie the guano as upon a scaffolding or platform rising out of the sea. The guano on this island lies on what may be termed a smooth, rounded mound, and is in some parts about one hundred and sixty feet thick. More than forty acres have been cut away from the side of the hill nearest to the vessels on which the guano is shipped. The birds which live and die upon these islands are principally of the Photo-Huenco species, and resemble blue and white pigeons with red bills. The white birds keep themselves separate from the blue, and hundreds of acres of land are completely covered with them. In addition to these, there are a number of sea-lions also to be found on these islands, which contribute somewhat to the quantity of ammonia created by the birds. Eggs and wings of birds, and teeth of sea-lions, are seen in abundance changed into ammonia in each and every part of the islands.