The total shipments from Baltimore, the only other centre of importance, were :-44,874,861 gal. in 1877, 37,712,900 in 1878, 23,322,482 in 1879, and only 14,780,980 in 1880.
Of the W. Indian Islands, Trinidad, Cuba, and Barbadoes are known to possess petroleum deposits, but they have been turned to little account; Barbadoee exported 2424/. worth in 1877, and 1437/. in 1878. Venezuela produces large quantities of rich bitumen fit for distilling, and minor contributions of petroleum ; a remarkable outburst of petroleum occurs between the Rio Tara and Zulia, one hole out of many giving 240 gal. an hour. In the neighbouring republic of Colombia (New Granada), petroleum ie met with between Escuque and Bettijoque. Peru has afforded petroleum from time immemorial. The Argentine Republic has recently commenced to develop its resources in petroleum at Laguna de Labrea, in Jujuy, where numerous springs exist. In S. Australia, a remarkable petroleum district has just been opened out on the banks of the Coorong, about 6 miles north of Salt Creek. A number of Australian capitalists have begun to work the petroleum-springs in the Poverty Bay dietriot of Auckland, New Zealand, and other springs are known of on the same coast.
There are three principal localities, each producing a distinct kind of oil :-(1) The Sugar Loaves, in Taranaki province ; (2) Poverty Bay, on the E. coast of the province of Auckland ; (3) Mauntahi, Waiapu, East Cape. The oil from the first has a very high ep. gr., 0.960-0.964 at 153° (60° F.). It has thus too much carbon in its composition for its commercial success as an illuminating-oil, but ie capable of producing a valuable lubricating-oil. It resembles oil occurring in Santa Barbara county, California. The second kind, from Waiapu, Poverty Bay, ie a true paraffin-oil, resembling the Canadian oil. By three successive distillations, and treatment with acids and alkalies, about 65 per cent. of a good illuminatiug-oil is obtainable, with a sp. gr. of 0'843. The third produces a pale-brown oil, nearly or quite transparent, of ep. gr. 0.829 at 153° (60° F.), burns well, contains only traces of paraffin, and produces 84 per cent. of an illuminating oil, fit for kerosene-lamps, by a single distillation ; by two more distillations, 66 per cent. of the
crude oil has a sp. gr. of 0.811, which is that of common kerosene. At Sugar Loaf Point, Taranaki, the petroleum oozes from cracks in trachyte breccia. Wells have been bored to the depth of many hundred feet, but no steady supply of oil has been obtained. Crude oil has a sp. gr. of 0.962 at 15i. (60° F.), and yields, by fractional distillation, oils having the following gravities :-2 per cent. of oil of sp. gr. 0.874, 10 per cent. at 0.893, 8 per cent. at 60 per oent. at 0.941 ; or total of 80 per cent. distilled off, with 6.1 per cent. solid bitumen, per cent. fixed carbon, and per oent. ash.
The following ie an analysis of the petroleum found at Waipawa River, Poverty Bay, Auckland : -2 per cent. of oil of ep. gr. 0.809 (colourless), per cent. at 0.826 (nearly colourless), per cent. at 0.836 (pale-yellow), per cent. at 0.850 (dark-yellow), 11.0 per cent. at (brown, [solid at 43° (40° F.)]), per cent. at 0.864, 21.25 per cent. paraffin-oil; or a total of 93.75 per cent. distilled off, and 6.25 per cent. of residue in the retort (pitch).
At Waiapu, East Coast, Auckland province, the crude oil has a sp. gr. of 0.872 at He (58° F.); boiling-point, 143° (290° F.); flashing-point, 110° (230° F.); a sample with a sp. gr. of 0'829 gives per cent. of oil of ep. gr. (colourless), per cent. at (pale coloured), 12.5 per cent. at 0.840, per cent. at 0.860, and 4.25 per cent. at or a total of 96.00 per cent. distilled off, and 4.00 per cent. of residue in the retort. Another analyis yielded 12.20 per cent. of sp. gr. 0.820 (fine lamp-oil), per cent. at 0.853 (inferior lamp-oil), 26.69 per cent. of lubricating-oil, per cent. of paraffin ; or a total of 90.64 per cent. distilled off, and 9.36 per cent. bituminous residue.
Boring and Pumping Oil-wells.-Ready-formed outlets for petroleum are rarely found, and usually the earth has to be bored for a considerable depth to reach the productive level, and the oil then generally requires to be pumped out. This branch of the subject divides itself into four principal heads-the "rig," the well, drilling-tools, and pumps.