“If you could be heated, laundried, lighted, bathed, and have your cooking done, without any trouble, and all for next door to nothing; if into the bargain you could raise spring cabbages for a mere trifle, and new potatoes all the year round, not to speak of obtaining all the motive and hydraulic power you required, you would probably wish to move into a neighbourhood where such desirable conditions prevailed.
“As a matter of fact, there is a place where all this—and a great deal more exists, but it is situated in a somewhat inaccessible part of Italy, rather too far off, under existing conditions, to catch the Tube to the City, or the Elevated Railroad to Broadway.
“The district of Pisa, in Tuscany, is largerly of volcanic origins. In some parts of the province, and more especially in the neighbourhood of the little town of Larderello, the boiling springs which exist in the subsoil issue to the surface in the form of numerous and powerful “gushers” or “geysers” of hot vapour or steam. These gushers, or jets of steam, are known locally as “saffioni,” and the evaporated steam finds its way into a large number of small pools or “lagoni.” Though these jets of steam issuing through fissures in the granite, must have existed for many thousands of years, it was not until about a hundred years ago that they were discovered to contain a substance of great commercial value. Some scientists visiting the pools, or “lagoni,” found out that the waters contained, in a state of dissolution, a very considerable quantity of boracic acid. It was soon discovered that the boracic acid came from the jets of steam issuing from the soil near by, and, provided means could be invented to evaporate the waters of the “lagoni,” the boracic acid would fetch a good price.
“Boracic acid was discovered in 1702, but as it has never been found possible to synthesize the product with a view to its artificial manufacture, chemists are dependent upon natural sources for its supply. Until comparatively recent times, boracic acid was in great request as an antiseptic, but has now been replaced by other and more powerful substances. Boracic acid continues, however, to be in great demand, both in its crude form and in the form of the various boraxes derived from it, for soldering, enameling, glazing, and dyeing purposes. It is likewise used in the manufacture of soap, and even as a substitute for that useful article.
“Most of the boracic acid in use to-day comes from Italy, especially from the Pisa district. Recently, huge deposits have been located in Asia Minor, but the war has prevented the development of these deposits for industrial purposes.
“The “saffioni” found around about Larderello are saturated with the acid, which, as the steam evaporates into the pools, settles at the bottom of the “lagoni.” It is supposed that the streams of hot steam passing at great pressure, and at a high temperature, through the underground fissures of the rock, act as a dissolvent upon the tourmaline in the granite, and separate the acid from the boron, carrying it automatically along to the surface.
“The first attempts made to evaporate the waters of the “lagoni,” so as to secure the acid, were very primitive. Ovens were bored around the pools. These ovens were filled with wood, and kept alight until the waters had evaporated. This was a long and tedious process, and by the time the boracic acid was secured it proved so costly as scarcely to pay for production.
“Other and more modern processes were afterwards tried, but none of them proved satisfactory until an Italian engineer hit upon the very simple idea of utilizing the “saffioni,” or steam jets themselves, as the heating power for the evaporization of the acid-laden waters. The natural pools into which the jets of steam projected the acid they contained were abandoned altogether, and around the aperture of each “saffioni” or jet of hot vapour, as it issued from the soil, there were built small reservoirs of rough masonry jointed with clay.These were filled with water from the pools, and the action of the hot vapour churning the water soon brought it almost to boiling-point. At the end of twenty-four hours it was found that the water contained about one and a half per cent. of acid. By means of a wooden pipe the water was conveyed into a second reservoir built round a second “saffioni,” where it was further enriched by acid. After being transferred into half-a-dozen different reservoirs built round different jets, the water was sent into a decanting tub or basin, where it deposited the earthy impurities held in suspense.
“From the decanting basin the water is sent into special evaporators. These evaporators consist of long wide sheets of un-dulated lead, two hundred and fifty feet in length and eight feet wide, turned up at each side. These leaden sheets are placed on an incline, and the acid-charged waters trickle slowly over the wavy sheets of lead, which are heated by hot steampipes passing underneath. As the acid-charged water trickles over the hot, wavy, leaden plates it evaporates under the action of the heat, and deposits the boracic acid.
“The hot steam is derived directly from the natural vapour underground, but instead of utilizing the ordinary “saffioni,” or vapour-jets, for the purposes, it was considered preferable to make separate artesian borings to a distance of one-hundred feet or so underground. The steam was tapped with such force, that unless special precautions had been taken beforehand the rush of subterranean vapour would have caused a serious accident. Indeed, the artesian borings brought up steam-jets with a pressure of no less than nine atmospheres at a speed of one-hundred and seventy-five yards to the second, and at the great heat, in some borings, of one-hundred and ninety degrees Centigrade or six-hundred and forty degrees Fahrenheit.
“The discovery that such vast subterranean power lay at the disposal of the engineers soon led to the installation of powerful dynamos. It was first found necessary to purify the stream of its gaseous matters, for otherwise the machinery would have quickly become corroded.
“Within a few years the engineers had tapped, by short artesian borings, quite a number of “hydro-volcanic” power-jets. A single one of these, the “Ponta Anna” bore, produces two-thousand three-hundred horse-power, whilst another, the “Venella” bore, produces one-thousand two-hundred and sixty horse-power.
“The power-houses were soon supplying hydro-volcanic energy to a considerable number of factories, and in what was formerly a deserted district there sprang up the town of Larderello. Not only so, but there ensued the natural desire to turn this volcanic power to domestic use, and some of the engineers and factory managers had their dwellings fitted up with piping, so as to get heat in winter and fuel for cooking, for the heat is sufficiently great to bake a joint in an oven in half an hour. It is, however, dangerous to “monkey about” with the subterranean forces of Nature, and early experiences were accompanied by a number of accidents and mishaps.
“One of the factory engineers, whose house had been fitted with the hydro-volcanic heating apparatus, was aroused in the middle of a heavy sleep by a roaring sound like a locomotive blowing off steam. He turned on the electric light—which was also supplied by the dynamos worked by volcanic power—to discover a geyser of boiling water bubbling up in the middle of his bedroom and filling the room with steam. He had just time to jump out of bed and make his way out into the street in his dressing-gown, when the geyser assumed gigantic proportions and burst with a roar through the roof of the house, soon reducing the entire building to pulp. It seems that, in some way, the control cap of one of the main tubes, as the steam issued from the bore, had become partially unscrewed, with the result that the full force of the bore had found its way into the engineer’s house and burst the hot-water piping under the floor of his bedroom.
“It took several hours before the geyser could be got under control.
“On another occasion an Italian cook, on returning from market and entering her kitchen, was horrified and amazed to discover the whole of her pots and pans on the long kitchen range jumping about as though bewitched. The range was heated by steam radiators from one of the volcanic bores, and the metal of the radiators was of an undulating wavy form. Owing to a sudden increase in the subterranean velocity of the steam jet from the bore, the steam had ruptured the control cocks and had come throbbing through the heaters in jerks, imparting a gyratory movement to every one of the kitchen utensils on the range.
“One morning, too, a stout factory manager had such a fright, whilst in his bath, that he resolved never again to take any baths the water of which was supplied by hydro-volcanic process. The bath was fitted with a hot and cold douche apparatus which, instead of descending from the roof over the bath, came from an aperture in the bottom of the bath-tub, in the form of an “ascending” douche, as it is called.
“On that particular occasion the main geyser from one of the bores had suddenly taken on a “spurt” of two or three minutes, causing the hot water in the main pipe to rush with increased velocity, and rupturing the control tap. The water, in the form of a hot and cold mixed “douche,” suddenly shot up from below the bath with such tremendous force as to rupture the rivets and send the man taking his bath three or four feet into the air before he could recover himself. Happily the mixture of cold with hot water prevented what might have been a serious accident.
“The municipal laundry, in which all the hot water is supplied from the bores, is another luxury due to the existence of hydro or thermo-volcanic power. Before the scientific system of controlling the steam at the output of the bores was brought to its present state of perfection, it not infrequently happened that a sudden wave of “power” would play havoc with the machinery which supplied the hot water to the laundry. On one occasion all the “laundry” of the town of Larderello was sent flying in all directions, and there being a high wind blowing at the time – many of the articles were recovered in the plain several miles away. All these little mishaps no longer occur, so perfectly are the main thermic-power bores now under control.
“The Larderello “saffioni” are invaluable to the local market gardeners, who are so able to regulate the heat of their hot-houses as to produce fruit and vegetables in abundance all the year round.
“The Larderello vapour jets and the intelligent industrial use to which they have been put by Italian engineers have attracted the attention of scientists to the immense possibilities that lie in the systematic and rational utilization of the hidden subterranean forces of Nature.”
Source of information:-
Sarti, Fabricio, The article ‘Harnessing a Volcano’ was published in ‘The Wide World Magazine – An illustrated Monthly Of True Narrative’, Vol. XLII – October 1918 To March 1919. George Newnes Ltd., Southampton St., Strand, London.
© Ray Spencer, The Journal Of Antiquities, 2016.