VOLCANIC STEAM IN ITALY 521 



placed by another, invented by Signor P. Bringhenti, in which the 

 dissolved gases (v. s.) are separated from the natural steam, thus 

 increasing the efficiency of the condensers. The pure steam, super- 

 heated with the aid of natural steam, is fed at a pressure of 1.25 

 atmospheres absolute into 3,000-kilowatt turbo-generators of the 

 Parsons type, of which two are in use and one is kept in reserve. 

 Each unit has a net efficiency of 2,500 kilowatts, and generates a 

 3-phase current at 4,000 volts, 50 periods. Step-up transformers of 

 the self-cooling oil type raise this voltage to 16,000 for distribution to 

 the various works, and to 32,000 to 38,000 for transmission to Siena 

 and Florence, Leghorn, Piombino, for use in iron and steel works, 

 and to the pyrites mines at Massa. The condensers, each with a 

 cooling area of 11,300 square feet, are placed below the turbines ; the 

 cooling water is driven through the tubes by centrifugal pumps and 

 thence to the refrigerating towers. Two hydraulic ejectors are 

 fitted to each condenser, and the condensate is removed by centrifu- 

 gal pumps. A second power station has recently been erected at 

 the Lago works for experimental purposes, including work on the 

 new type of evaporator. 



The water containing boric acid is evaporated by natural steam 

 in shallow lead-lined basins arranged on a slightly inclined plane 

 and operated on the counter-current principle. When the boric-acid 

 content has increased to about 8 per cent, the liquid is cooled and 

 the crude acid, up to 99 per cent purity, is crystallized out. This 

 acid is then purified by recrystallization. At Larderello there is a 

 small production of borax from boric acid and sodium carbonate, and 

 at the Castelnuovo works an output of about 10 tons per day of 

 ammonium carbonate. 



Looking to the future, it appears more than probable that the pro- 

 duction of power and chemicals with the aid of natural steam will not 

 long be confined to Tuscany. Already the volcanic districts of 

 Vesuvius, Etna, and the islands of Eolie (Lipari) are being studied. 

 Outside Italy like investigations are being pursued in America on 

 the steam springs of California, Chile, and Bolivia; and attention 

 will doubtless be given to similar fields in Alaska, New Zealand, and 

 especially Japan, where such volcanic manifestations are numerous. 

 To Italy, however, will belong the credit of having initiated this 

 method of tapping a supply of energy which, in spite of the atten- 

 tion it has attracted, has been running to waste for centuries, and 

 thus providing yet another method of " utilizing the forces of nature 

 for the benefit of mankind." 



