Salt pans

There have been several attempts to establish the industry of extracting salt from sea water in the archipelago, but almost always with discouraging results. The earliest attempt dates from 1792, when the royal decree (alvará) of 20 November of that year permitted Tomás Watts, Francisco Martins da Luz and João José de Basto ‘to establish fisheries and salt works throughout the state of Madeira and at the beach called Formosa’. This attempt was followed by another from Francisco Vicente Espinosa da Câmara, who in 1823 applied for the exclusive right to make salt in Madeira for 30 years, setting out some means of obtaining this product on advantageous terms.

At Praia Formosa (‘beautiful beach’) there are traces of old installations for crystallising salt, probably built by the first people to try salt-making here. Very close to this locality (sítio), at Ponta da Cruz (‘point of the cross’), trials to produce salt were made about 15 years ago, but they came to nothing because the sea water had to be raised to a great height to get it into the reservoirs. It was José da Corte who tried to establish salt pans at Ponta da Cruz, but once the tuna-canning factory was set up, all attempts to extract salt at that locality ceased entirely.

Around 1865 Jacinto António de Sousa had salt pans built at Paul do Mar (‘marsh by the sea’), in the localities of Lagoas (‘ponds’) and Serra da Cruz (‘upland of the cross’). These passed, we believe around 1878, into the possession of Filipe António Gonçalves. Some 15 to 20 years ago other salt pans were established near the old ones, owned by José Maurício Gomes, João Martins da Silva, José da Corte and Alexandre da Silva (1921). A great deal of salt, not always of poor quality, was made in both the new and the old salt pans, but this did not prevent both from being abandoned because they yielded little profit, or perhaps losses, to their owners. Clay was even imported from Portugal to line the floors and walls of the reservoirs of these later salt pans.

We also know of two other attempts to extract salt in Madeira, one at the locality of Fajã da Areia (‘sand flat’), in São Vicente, and the other in the parish (freguesia) of Caniçal (‘reed bed’), neither of which produced encouraging results either. José Maurício Gomes and J. Pontes Leça set up and ran the Caniçal salt pans.

On Porto Santo (‘holy harbour’), too, there were some attempts to establish the industry of extracting salt from sea water. The earliest was that of Isidoro da Silva, who spent considerable capital building salt pans at the locality of Fontinha (‘little spring’). In 1890 and the years immediately following, Augusto de Nóbrega Noronha succeeded in extracting a great deal of salt from salt pans he had built at Serra de Fora (‘outer upland’), in the north of the island. Around 1903 further salt pans were established at the same locality, owned by Dr António Luís Pimenta; these, however, did not give satisfactory results, owing, it was said, to defects in the construction of the reservoirs meant to receive the water.

To operate salt pans in the archipelago, the water must be raised by machinery of some kind, since the shape of the coast means the reservoirs cannot lie below sea level. This circumstance on the one hand, and on the other a certain slowness in evaporation – because the sky is often overcast in summer and the atmosphere usually holds a large amount of water vapour – make salt-making more costly and difficult here than on the mainland. This does not mean that it cannot be carried on, perhaps even on advantageous terms, if certain rules are observed to which due attention has not always been paid until now.

The Paul do Mar salt pans did not give encouraging results because they were built in a spot little swept by the winds and steam engines were needed to raise the water. At Caniçal, however, there is reason to believe that salt extraction may yet prove profitable, provided care is taken to cement the reservoirs so that the product does not come out laden with impurities, as has already happened. There, as on Porto Santo, wind-driven pumps can be used to raise the water, a great saving in this operation. Indeed, it was with the help of one of these machines, and with reservoirs built as described above, that the late Augusto de Nóbrega Noronha obtained salt on that island as perfect as that which comes from Portugal.

The working of salt pans in this archipelago deserves special study, as it would soften the unfavourable impressions that have persisted here about the various failures surrounding this valued industry. To that end, we shall transcribe some passages from a fine article by the distinguished naval officer and academician Admiral Hugo de Lacerda, which contains valuable information on this important subject.

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A simple comparison of the technical factors that may be considered fundamental to the question at hand, between those here and those on the Portuguese mainland, may, I believe, already shed some light. As is well known, mainland Portugal is one of the principal producers of salt: there are vast salt pans, or salt marshes, in the Ria de Aveiro, in the Mondego estuary, on the Tagus as far as Vila Franca and on the Ribatejo bank, on the River Sado as far as Alcácer do Sal, and also in the Algarve at Faro, Tavira and Portimão. Let us see. – As to the degree of salinity of the water and its purity, only advantages can be seen in this archipelago. The drawback I have heard mentioned, that salinity here is greater than on the mainland, can only hold in the opposite sense; besides, it is not because the mainland salt marshes are situated (with the exception of those at Faro) in river regions that they will receive less dense water, since they operate in the dry seasons. – With regard to the greater ease of filling the reservoirs, there can be no doubt that marked advantages exist on the mainland, where the flow of the highest tides alone is enough to let the water in freely; and the facilities are all the better given the greater stillness of river areas. The quantity of water to be treated is considerable, because each litre can yield only about twenty grams of sodium chloride; nevertheless, since the wind can be relied upon, the windmill can solve the difficulty more economically, all the more so as it can also be put to other uses. It should be noted that in Italy, also a great producer of salt, the Mediterranean tides rise at most 0.3 m above mean level, so it is only natural that recourse must be had there to more or less costly artificial processes. – As regards waterproofing the floors and walls of the reservoirs, which seems to have been the main cause of the failures mentioned, there is again no doubt about the advantages on the mainland. But if the lining, as was done on Porto Santo, cracked, cracks are less to be expected with modern reinforced-concrete methods, which in this case need not even allow for appreciable loads, a simple wire mesh perhaps sufficing as reinforcement; besides, good waterproofing processes already exist, the cracks themselves can be remedied, and one can count on the covering of liquid, at least in the season of highest temperatures in the sun. In Moçâmedes, I am told that the salt for curing the fish, so plentiful there, is made in reservoirs lined with concrete, naturally reinforced. The Encyclopaedia Britannica refers to reservoirs of this kind. – It is a condition that there be no rain during the production period, and this is identical and in practice met in both regions. – Heat is an important factor, the one to judge being above all direct solar radiation; as for heat in the shade, there should be some advantage here, but with regard to direct heat in the open sun there may be doubts, even in the coastal places relevant to the question, the sunniest, namely those of Porto Santo; nevertheless, one of the experiments has already shown that abundant salt could be obtained. – Capital importance must be attributed to the wind. In much of the south of Madeira relatively little action of this kind can be counted on; but on the north side, and on the south side from Machico eastwards, and above all on Porto Santo, judging by the winds that blow at Ponta de São Lourenço, the differences should not be so marked in relation to the strong northerlies of the mainland coast in the summer months. In this respect, too, that experiment which produced abundant salt (albeit of poor quality) must also be taken into consideration.

Lastly, there is the relative humidity of the atmosphere which, being considerable, must counteract the action of the sun and wind, reducing evaporation. This condition is exactly the same in the two regions considered in summer, because in winter (it is always worth repeating) the advantages here are considerably greater.

To sum up: as to technique, provided it is respected and the sites are well chosen, there seems no reason to think that good and abundant salt cannot be obtained here. The question is thus mainly a financial one, of reasonable profits: on one side the greater expense of lining the reservoirs and raising the water; on the other the cost of shipping salt from the mainland to here, and also the higher price of labour, both in the initial installation and in the production itself.

But this does not mean that there is no need to turn to a good expert, for both matters, assisted by staff trained in the work. And should a new, well-directed attempt perhaps be desired, would it not be possible to find a good printed guide, on both the technical and the financial side? The Dicionário Português Ilustrado refers to an article by a Portuguese engineer on the subject.

It must also be considered that Madeira may at any moment find itself isolated, or nearly so, and salt is among the first necessities, so much so that in some places it is a principal object of barter.’