The Gold of the Orba and Its History
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THE GOLD OF THE ORBA AND ITS HISTORY 1 THE GOLD OF THE ORBA AND ITS HISTORY 2 THE GOLD OF THE ORBA AND ITS HISTORY The gold of the Orba and its history in the “Cascina Merlanetta” museum in Casal Cermelli 3 THE GOLD OF THE ORBA AND ITS HISTORY 4 IN THE MUSEUMTHE GOLD OF “CASCINA OF THE ORBAMERLANETTA” AND ITS HISTORYIN CASAL CERMELLI Like other gold rivers in the Val Padana, the Orba stream has been the subject of intense “gold fishing” over the centuries and in some periods of real industrial cultivation. The system and means used were simple and ancient. Once the richer area was recognized with small samples, the coarse material was sieved and the sand was washed, made to slide on a small grooved axis suitably arranged so that the stream of water dragged the light part away. The concentrate of heavy materials, trapped between the grooves, was finished with the “cupou”, a large wooden plate which, stirred with skill in the water and with a rotating movement, retained only gold dust on the bottom. A small magnet was of great help in eliminating the abundant magnetite (iron ore) before proceeding with the final washing. In addition to gold, the magnetic concentrate was also recovered: the finest part was sold as “dusting” (black powder used in the past to dry the ink), the coarser and more abundant part was instead sold or sold to modest foundries or to blacksmith’s workshops that used it mainly for welding. Many elderly Casalcermellesi remember that fathers and grandparents often went, even by bicycle, to Milan, Genoa and even Bologna to sell some bags of dusting. 3 THE GOLD OF THE ORBA AND ITS HISTORY In fact, there were many who, in past times and until not many decades ago, dedicated themselves to “gold fishing” in the Orba alternating this activity with the care of the fields. The families Nizzo, Testa, Bianchi, Grassano and Bastianino operated in Casal Cermelli in Portanova i Marzola and Ricagni. The work day made two or three grams of gold up to seven or eight grams in particularly rich points and in lucky times. The casalcermellese Biagio Testa remembered that in the thirties of the last century his father and grandfather in a single day managed to put together eighteen grams of the precious metal. The system and means used were simple and ancient. Once the richer area was recognized with small samples, the coarse material was sieved and the sand was washed, made to slide on a small grooved axis suitably arranged so that the stream of water dragged the light part away. The concentrate of heavy materials, trapped between the grooves, was finished with the “cupou”, a large wooden plate which, stirred with skill in the water and with a rotating movement, retained only gold dust on the bottom. A small magnet was of great help in eliminating the abundant magnetite (iron ore) before proceeding with the final washing. In addition to gold, the magnetic concentrate was also recovered: the finest part was sold as “dusting” (black powder used in the past to dry the ink), the coarser and more abundant part was instead sold or sold to modest foundries or to blacksmith’s workshops that used it mainly for welding. Many elderly Casalcermellesi remember that fathers and grandparents often went, even by bicycle, to Milan, Genoa and even Bologna to sell some bags of dusting. So far the oral traditions but much more ancient and consistent has been the activity generated by the presence of gold in the sands of the Orba stream, testified by the abundant paper documentation kept ANCIENT GOLD RESEARCH TOOLS USED BY LOCAL POPULATION 4 IN THE MUSEUMTHE GOLD OF “CASCINA OF THE ORBAMERLANETTA” AND ITS HISTORYIN CASAL CERMELLI in the archive of the Cascina Merlanetta Museum, which allows you to have a general and as complete as possible on the subject. After the Celto-Ligurians it was the Romans who massively exploited the gold sands of the Orba using, according to local legend, the work of Christian slaves at the two settlements called Rondinaria and Rondinella: the first located between Lerma and Silvano d’Orba, the second at the Merlana farmhouse in the territory of Portanova di Casal Cermelli. The existence of Rondinaria is evidenced by the presence of aurifodine residues (deposits of pebbles resulting from the processing of gold sands) in the low valleys of the Piota and Gorzente streams, those of Rondinella from the persistent memory of the “Valley of Christians” and the discovery, in 1948, of a necropolis dated between the middle of the second and the first years of the first century BC Towards the year 1000 the Orba was mentioned among the gold rivers located in the jurisdiction of the Royal Chamber of Pavia, which boasted rights to the metal collected by the “aurilevatores”. In the early 1200s the right to “colligere aurum in flumine Urba” was the prerogative of the Marquis del REPRODUCTION OF THE CHRISTMAS PAINTER PROTO: RONDINARIA WORK PERFORMED ON THE OCCASION OF THE WORLD CHAMPIONSHIP OF THE GOLDEN SEARCHERS, OVADA 1985 early 1200s the right to “colligere aurum in flumine Urba” was the prerogative of the Marquis del Towards the year 1000 the Orba was mentioned among the gold rivers located in the jurisdiction of the Royal Chamber of Pavia, which boasted rights to the metal collected by the “aurilevatores”. In the early 1200s the right to “colligere aurum in flumine Urba” was the prerogative of the Marquis del Bosco, and the seekers who operated without their license or did not pay what was agreed upon were driven out of the river and their tools destroyed. The collection of gold continued for several centuries by local people who sold directly to Genoese merchants, as is learned from various texts by authors of the late eighteenth and early nineteenth 5 THE GOLD OF THE ORBA AND ITS HISTORY 1212 - THE MARCHESE DEL BOSCO ENSURES THE RIGHT OF GOLD COLLECTION IN THE ORBA STREAM decades. The gold of the Orba comes from the mines of the Val Gorzente, subject to limited exploitation already at the time of the Dukes of Mantua (and Marquises of Monferrato), between the ‘500 and the’ 600. In the second half of the 19th century a new phase of research and cultivation of the mines began and numerous researches were also developed in the lower Orba valley, especially by French companies.In 1866 Messrs Serra and Paulin obtained a research permit for gold minerals in the Pedaggera area, in the municipality of Capriata and the following year the “Lyonese Anonymous Company of the Reserves 6 IN THE MUSEUMTHE GOLD OF “CASCINA OF THE ORBAMERLANETTA” AND ITS HISTORYIN CASAL CERMELLI aurifers of the Apennines “conquers a similar permit in the nearby Rio Secco in the municipality of Carpeneto. The permissionaries, however, had to deal with the owners of the land to which the laws of the time recognized certain rights that ended up hindering searches. A first attempt at industrial exploitation took place in Casal Cermelli in the late 1800s by the “Italo-Swiss Society for the gold deposits of Liguria” legally represented by the engineer Emilio Berio domiciled in the village and chaired by Dr. Stefano Sturla native of Carasco and resident in Genoa. The research gave satisfactory results so much so that we proceeded to the purchase and installation, in 1887, of a floating dredger for the collection and washing of gold sands, for the then very high sum of 250,000 lire: located near Cascina Merlanetta , it could treat up to two thousand cubic meters of material per day by recovering 50% of the gold contained. In 1888 the company obtained, among numerous bureaucratic hindrances and limitations of all sorts, the concession to “carry out excavations in the riverbed of the Orba stream along its entire path for the treatment of gold sands”. The concession initially lasting two years, was extended to fifty after the presentation of the final technical project, of which the Museum keeps the documentation. On September 27, 1890, the Italian-Swiss company had the definitive concession and the engineer Ernesto Felice Lacour took over to represent it, modifying the dredger with the introduction of a system patented by him to better operate in the difficult alluvial sediments of the Orba torrent. During 1891 the plant that was not yet operating in the richest area, gave a daily product of one hundred grams of gold and it was expected to triple it in the most favorable area. During the first months of 1892 the dredge was first damaged, due to the large boulders with which the alluvial deposits of the stream are full, then completely destroyed by the ruinous flood of 13 October 1892. The succeeding Italian-Dutch company left the company the following year, transferring the remains of the dredger and its speculative activities to Vigevano sul Ticino. DRAGA OF THE ITALIAN-SWISS SOCIETY IN ORBA, IN CASALCERMELLI, IN 1887 7 THE GOLD OF THE ORBA AND ITS HISTORY Other attempts followed by the De Ferrari brothers of Genoa, who in 1902 obtained authorizations for surveys and explorations on both the Orba stream and the Piota tributary. Another very important phase of exploitation occurs in the autarchic period preceding the Second World War by Giuseppe Perino’s “Orba Minerals Society”, owner of a sandpit in Portanova and a foundry in Genoa Pontedecimo. MANUAL MAGNETIC SEPARATOR In the impossibility of importing machinery from abroad due to the sanctions, Perino built some machinery patented by him to separate the heavy minerals from the sands, consisting of magnetic and electromagnetic sorters, shock tables and grates for collecting heavy minerals directly in the Orba : in addition to gold, “iron oxide” magnetite and ilmenite (iron and titanium oxide) were recovered which were used in the Pontedecimo plant.