Proceeding along the coast the next railway centre is in the nitrate district, where a number of short railways connect Iquique, Pisagua, Tocapilla, Caleta Buena and other towns in that district, making up a total of nearly four hundred miles. Antofagasta also has some short spurs which run back into the mineral regions, and carry the ore down to that port. The principal line at this place, however, is the international railway which runs from Antofagasta to the Bolivian city of Oruro, and there connects with a Bolivian railway which runs to the capital, La Paz. This railway is constructed upon an extremely narrow gauge of thirty inches. The Chilean section of the railway ends at Ollague, a distance of two hundred and seventy-five miles. This railway was originally built to aid in developing some of the rich mines in Potosi, Bolivia. By the aid of a government subsidy, it was finally completed in 1892. This is the largest private railway enterprise in Chile. It would be difficult to imagine a more dreary route over which a railway could be planned than the Chilean section of this railway. At first the question of a water supply for the engines was a serious problem, as the water which they were able to secure easily was so permeated with minerals that it destroyed the boilers. The concession of supplying the city of Antofagasta with water was finally conceded to the railway company, and, with that monopoly as an aid, pipes were laid for a distance of more than two hundred miles to supply the water tanks of the railway and the city of Antofagasta. The freight hauled over this road is quite considerable, since it is one of the two lines which at present reach from the coast to the republic of Bolivia. Half or more of the freight, to and from that inland republic, is shipped by this route, in addition to the product of the mines of the famous Huanchaca Company. In the province of Coquimbo there are several short sections of railroad, all of which were constructed by the government. In all these lines total about two hundred miles. It will not be long until Coquimbo will be connected with the main line by a longitudinal railway. In the northern section of the country there are no less than fourteen different lines, and at least three different gauges of track.