Mona Island – The Mining Period, 1848 -1927
An extract from Isla Mona, Vol. II, Puerto Rico Junta de Calidad Ambiental, where text citations are described.
Rainwater seeping through the limestone during some wetter period since Mona and Monito emerged from the sea dissolved out numerous caverns. Deposits of what is referred to as “guano” to depths of six feet on the cave floors indicate that large colonies of fish-eating bats must have at one time roosted in these caves (Gile & Carrera, Kaye). The guano is bat manure decomposed and mixed with limestone detritus. It may contain as much as 20 per cent phosphate (P2O6) (Cadilla & Vazquez), useful as a fertilizer for agricultural crops. The extraction of these deposits for commercial purposes characterizes an important period in the history of Mona and Monito islands.
Reported to be useful as a fertilizer as early as the late 18th Century (Abbad y Lasiera) and possibly known to the Tainos long before that, the guano deposits became attractive commercially only after the menace of the pirates was gone. Extraction of guano, presumably clandestine, was reported as early as 1848 (Spain 1848).
By 1854 the Spanish Government had received numerous applications for exploitation rights (Spain 1854). In response to the application from a Baltimore company submitted in 1856 (U. S. Dept. State 1856) the Captain General of Puerto Rico in that year sent an expedition to examine the deposits. Two large American vessels were found loading guano without authorization. The masters of these vessels refused to recognize Spanish authority. As a result the Spanish warship Bazan was made available by the U. S. Consul to the island in May of that year. He found an American ship being loaded by 12 laborers said to be from St. Thomas. The Captain alleged that he didn’t know the ownership of the island. He was requested to stop loading forthwith and to withdraw.
Incredibly Monito was reported as a source of the guano extracted (U. S. Dept. State 1856). The undercut cliffs made it next to impossible even to moor a ship to this rock, although there is an exposed anchorage nearby (Sanchez de Toca) .The exploitation of these deposits, also reported subsequently (Cherruca) may explain how rats got there.
The Government of Puerto Rico denied the American applications in 1858, evidently including one from the U. S. Consul for himself (U. S. Dept. State 1860), and proposed to send 30 tons of the material to Cadiz and London for assay (P. R. Dept. Interior ; Acosta y Calvo). The Bazan returned to Mona and Monito late that year, mapped 17 caves on Mona and one on Monito, and brought back samples of guano and sea birds, Taino relics from the caves, and large white sponges (Anon. 1858). The London assay, not actually made until 1861, showed the guano to have an average specific gravity of 1.82 and to contain about 24% phosphoric acid (Vasconi & Vasconi). The Civil War blockade, whch brought Confederate warships to Puerto Rican waters, undoubtedly obstructed exploitation during the next few years. Commercial statistics from 1861 to 1876 record the shipment of only about 10 tons (P. R. Intendencia).
The first official concession to extract guano from Mona was made in 1871 to an Englishman named Huighes (Jackson). BY 1874 this had lapsed and a second concession was given to a Puerto Rican, Manuel Homedes y Cabrera (P. R. Dept. Interior). This also lapsed unused. A third concession of 1877 was given to Miguel Porrata Doria of Fajardo and Juan Contreras Martinez, a Spanish Brigadier (Spain 1877). The first legal mining enterprise was undertaken in 1878 by the Sociedad Porrata Doria Contreras y Cia.
In 1881, after a year of inactivity, John G. Miller, a noted geologist from Ottawa, Canada, took charge of mining operations. With him was Carlos Miguel Iglesias y Mons (Bruni y Font; U. S. Dept Interior). Miller set up headquarters near Cueva de Pajaro, and screening and sun-drying fascilities capable of processing 100 tons per day (Bruni y Font). In addition to mineralogical studies (Shepard), he collected an impressive collection of Taino relics (Bruni y Font) from the eastern part of the island. After exploiting the caves there he planned to proceed to those of Sardinera and Uvero (Miller).
The names of the caves proposed for mining during this venture were Mayaguez, Caigo o no Caigo, Los Ingleses, Escrita, Agua, Lirio, Puente, Alemana, Capitan, Canada, Pajaros, and Esta (P. R. Interior).
The guano, dug up with picks, bars and shovels, was transported in wheelbarrows and in the three largest cave systems (Briggs) also in tramcars on metal rails laid on graded courses. From cave mouths directly above the water, the guano, in baskets, was lowered with ropes to boats that transported it to Playa de Pajaros for processing (Brusi y Font). Markets included England, France, and the United States (P. R. Dept. Interior).
Retention of miners was evidently a problem. During 1882 the number employed varied from 31 to 63 per month (Miller), when 40 tons were being mined daily. It was reported that 76 miners had been brought from Guadeloupe (Spain 1882; P. R. Dept. Interior). Yet the following year the miners, about 100 in all, were mostly Dominicans and Puerto Ricans (Brusi y Font).
Loading was a precarious operation. Ships lay anchored or moored to buoys and exposed to the open sea just outside the reef off Playa de Pajaros. Using 5 to 8 men from ashore as well as the ship’s crews, loading required up to a month even in favorable weather (Miller).
There the Olive Cosby, a Maine schooner, met her fate on December 27,1883 (U. S. Dept State 1884a). A direct onshore wind from east by south and a surging heavy sea came up while she was lying at buoy almost fully loaded. The master started to make sail, but before he had headway the mooring chain parted. He dropped a port anchor, but the chain parted immediately also, and the vessel was driven broadside onto the reef, a total wreck. The crew was rescued from onshore.
An almost identical disaster befell the 310-ton brig, F. H. Todd on February 13, 1884, less than two months later (U. S. Dept State 1884b). A southeast wind came up on the 12th and a heavy sea commenced to roll in. The brig, awaiting cargo, lost one anchor that day. On the 13th a violent squall parted a chain to one anchor and a hawser to a second, dragging a third until she went into the reef, becoming completely wrecked. The crew was rescued.
The unpredictable nature of Mona’s waters was borne out by a third tragedy, that of the 208-ton schooner, John H. Pearsons at the same location on November 22,1884 (U. S. Dept State 1884c). Attempting to shift anchorage, the vessel lost headway when the wind died, and the current swept her onto the reef, where she was reduced to a total wreck in a very short time.
A significant part of the first venture was soon over, with the main source of guano, Cueva de Pajaro, nearly worked out by 1884 (Brusi y Font). The next year, at a time that the miners were restive, Miller found it necessary to make a trip to Mayaguez for provisions. Wishing to return as soon as possible, he disregarded warnings of local seamen as to threatening weather and set out in his open sloop. Seventeen days after his departure identifiable remains of his boat washed up on the rocky shore of Mona (Davoine).As a result, mining operations were paralyzed for three years.
The end of the first mining venture did not result from a lack of guano. It was estimated in 1887 that in 22 caves there was a total of 462,000 tons of guano (Davoine). Nevertheless, mining ceased in 1889 after 31,000 metric tons (38 cargos) of guano had been shipped (P. R. Dept. Treasury 1903).
With the departure of the miners, the island became a quiet port for a few fishermen. Goats and cattle, in addition to the pigs, had gone wild (Churruca).
A second mining venture began in 1890. At that time Anton Mobins, a Germnan, subleased the Porrata Doria concession (P. R. Dept. Interior).It was transferred again in 1894 to Francisco Blanes y Mestre of Palma de Mayorca (Spain 1894). All but the most remote caves on the north side of the island were worked (P. R> Dept Interior). At the height of production 300 to 400 men were employed (Hubener).
Again the difficulties of loading the ships were critical (Hubener; P. R. Off. Gov.1902; Carlo).The reefs at Playa de Pajaros were blasted out to facilitate lightering to ships anchored outside. During the period 1890-1892 at least 30 ships were loaded in this way (P. R. Dept. Treasury 1904). In rough weather not only was lightering impossible, but at times the ships were forced to put to sea, and both ships and lighters were lost.
From 1891 through 1899, a total of 113,000 metric tons of guano were shipped from Mona, mostly going to England, Holland, Germany. Italy, and the United States (P. R. Intendencia; Hill; P. R. Dept. Treasury 1904b; U. S. Dept. War).
The discovery of better phosphate sources in Florida and Tunis was blamed for termination of operations in 1896 (P. R. Inst. Culture). The equipment was withdrawn (P. R. Provincial Commission) and by 1898 the population of the island dwindled to six.
The mining colony must have had a heavy impact on local sources of food. In 1898 three men were used to hunt goats and pigs continuously (Hubener). The wild pigs at that time must have become scarce because one report (apparently incorrectly) considered them exterminated (Hubener). Other local foods included fish, turtles, turtle eggs, sea birds eggs, pigeons, and thrushes.
In August 1888 a franchise was given to Carlos Iglesias to farm between the escarpment and the sea (Spain 1888). In 1884 Iglesias apparently had cleared land near Uvero and sold charcoal to the miners. He planted Guinea grass and walled in pig pastures with local stones. He raised corn, vegetables, plantains, fruits, cattle, and swine (Barber). In 1896 he was poisoned, reportedly by liquor intended for the captain of a guano ship that foundered off Uvero.
The mechanism for Mona Light, shipped from France, was nearly lost when the sloop San Antonio ran aground (P. R. Inst. Culture). A base was first constructed above Cueva de la Escalera with materials transported up through the cave (Hubener; Carlo 1951). A lighthouse attendant was living on Mona by 1898.
By 1898 the entire island had been searched for treasure and yet the fever persisted (Hubener). Even the Spanish Government took part. Among other things cannon balls were found on the coastal plain (Hubener).
With the change to American sovereignty in 1898 Mona was publicized for settlement. Newspapers in Boston and New York heralded Mona as the “pearl of the Antilles” an “uninhabited paradise” that would grow every kind of tropical crop, a nesting place of thousands of green turtles and surrounded by waters teeming with the finest varieties of fish (Anonymous 1899; 1899?). The lack of a resident population was considered “hard to surmise” Washington received at least 40 requests for rights to use the island (U. S.Dept. Interior 1898:1919). Mona and Monito, property of the U. S. Government after the war, all but a 235-acre lighthouse reservation, were in 1903 transferred to Porto Rico.
At that time a third mining venture began, with the island under the administration of the Porto Rico Department of the Interior. The Porrata Doria concession was terminated (P. R. Dept. Treasury 1904b) and a 40-year franchise was granted to Percy Saint. In December 1905, before any guano extraction had begun, this was transferred to the Mona Island Phosphate Company of Stockbridge, Massachusetts, of which Saint was Vice-President and General Manager (P.R. Dept. Interior; P. R. Inst. Cultura; U. S. Dept Interior 1898, 1919).
The dates of operation are not certain, but as late as 1909 a report anticipated that extraction would take place “very soon” (U. S. Dept Commerce and Labor 1909). Among others, the caves of Sardinera and El Capitan were worked. At El Capitan a chute was used for transporting the guano from the cliffs to the beach (Great Britain).
Interest in the phosphate increased with the approach of the World War. A German company is said to have purchased an option to the deposits (U. S. Dept. of Commerce 1922) and a British purchaser also appeared but the war terminated these arrangements. Meanwhile, the abnormally high prices evidently stimulated production by the Mona Island Phosphate Company. By 1920 the most accessible deposits had been worked out (Carlo 1951). In 1922 the franchise was sold to Chatham Coal and Coke Company of Savannah, Georgia, under the impression that between one and two million tons of guano remained. This company apparently did no extraction (U, S, Dept. Commerce 1922). The franchise was terminated in 1924 (P. R. Dept. Interior) and few workers were reported there in 1927 (Lobeck).
By 1903 the first site of the lighthouse had been abandoned because at that location the light was obscured from the East to the South Southeast (U. S. treasury 1902). A new location was selected farther north (P. R. Inst. Culture; Esteves Volkers). A narrow-gage railroad was built on the plateau from the Cueva de Escalera to the new site (U. S. Dept. Justice 1907). The landing below Cueva de Escalera was destroyed by a storm in August 1903 (U, S, Dept. Commerce and Labor 1903) and replaced at Playa de Pajaros.
The entire 800-acre coastal plain of the island was under agricultural permit during part of the third venture, evidently mostly as pasture (P. R. Dept. Agr ). From 1910 to the end of the mining period a Mrs. Eugenia (Doña Geña) Rodriguez provided food for the miners by hunting, fishing, and farming (Rodriguez). She and her two sons lived in a cave at Uvero. A third son, buried nearby, died reportedly of pneumonia (Barber). In 1922 the families were farming 32 acres (P. R. Dept. Interior). Crops included corn, squash, watermelons, pigeonpeas, beans, onions, sweet potatoes, peanuts, tobacco, cotton, sugar cane, and papayas (Rodriguez).
The wild goats and pigs, although hunted continuously, evidently thrived during this period. They were referred to as abundant in 1917 (P. R. Off. Gov. 1917, 1919; Schmidt 1925; Dillon; and 1927 Lobeck).
Scientific interest in the island increased notably in the second decade of the century. Studies of the insects were published in 1913 (Ramos), of spiders in 1915 (Lutz), and of the flora the same year (Britton). A land survey was made in 1917 by the Puerto Rico Department of the Interior (P. R. Off. Gov. 1917). Old trails to Bajura de Uvero (de las cerezas) El Corral, y Cuevas del Centro were mapped. The surveyors suggested that the island might be used for sisal (P. R. Off. Gov. 1917) and as in southwestern Puerto Rico, this plant was evidently introduced at that time near the lighthouse where it still survives.
Mona was formally proposed for a penitentiary in the Puerto Rico House of Delegates in 1915 (P. R. House of Delegates 1915). The proposal, apparently never approved, provided that each prisoner cultivate two cuerdas for his benefit and spend three days each week extracting guano, to be sold, at cost, to Puerto Rican farmers. Instead, except for the lighthouse reservation, Mona, together with Monito in 1919 was proclaimed an Insular Forest, transferring its administration from the Department of the Interior to the Department of Agriculture and Labor (P. R. Dept. Agr.) . By that time most of the forest had been cut over for fuelwood or removed entirely to provide pasture or for cultivation. Reportedly several hundred tons of lignumvitae, its oily wood useful for bearings, had been exported, evidently sometime after 1840, and probably during the early Mining Periiod (P. R. Dept. Agr.; P. R. Intendencia).
The hurricane of September 1921 carried off the roof of a lighthouse storeroom and damaged the kitchen and the tramway (U. S. Dept Commerce 1922). The inspection report emphasized the difficulties of transportation to the lighthouse, involving an approach with an onshore wind over reefs, a mile of foot travel along the beach, a rail tramway up a 50% slope to a cave to a stairway through the cave, and then another 6,000 feet by tramcar subject to frequent derailment because the 22-year-old tramway was in a state of collapse. Even walking was difficult because of the cactus. By 1924 an improved foot road was constructed between Playa de Pajaro and the Cueva de Escalera. In 1925, with a canopy on top, the tramcar was drawn by “Macario” a disdainful burro (Dillon). The construction of an automobile road was under way by 1927 (U. S. Dept. Commerce 1927).
Three shipwrecks believed to date from the Mining Period, all schooners, have been mapped (Fritz and Pilkey). One, La Engracia, struck the cliff near Cape Barrionuevo and lies in about 100 feet of water. The story is told that a single survivor swam from there to Sardinera (Barber). The other ships, probably guano carriers, lie off Playa de Pajaros and the south coast of Punta Caigo o No Caigo. A launch was disabled off Mona in 1913 requiring Coast Guard assistance to rescue seven persons (U. S. Dept. Commerce 1913).
Treasure hunting continued during the Third Venture. A systematic search was undertaken from 1922 to 1924 by a man named Erickson. He built a cabin near the south end of Playa de Pajaros, but became mentally deranged before he left the island and his findings, if any, are not recorded (Martin; Rodriguez).
The continuing significance of the isolation of Mona was evident in 1923 when a cache of 200 cases of smuggled liquor, French perfumes, and heroin valued at more than $75,000 was found in one of the caves (Anon. 1923).
In less than 80 years, from 1848 to 1927, the Mining Period was over. Shipment records for the 19th Century total 145,000 metric tons. Records have been found of only 2,980 metric tons shipped during the 20th Century. It appears that shipments were negligible before 1910 and after 1920. Royalty payments by the Mona Island Phosphate Company did not in any year exceed the $1,800 minimum corresponding to 2,727 metric tons, so the shipments for the period from 1910 to 1918 could not have exceeded 25,000 metric tons. This would make the production for the entire period something between 148,000 and 173,000 metric tons.
The guano remaining consists of small residuals in the caves worked, larger deposits north of Punta Este (Briggs; Cadilla and Vazquez) and possibly also hidden deposits as yet undiscovered. A recent estimate of residual guano, based on cave measurements, is 25,500 m3 (Briggs). This is equivalent to 29,000 to 46,000 metric tons, depending on the specific gravity of the material, found to be 1.82 in 1868 (Vasconi y Vasconi) and 1.15 recently (Cadilla & Vazquez). Added to the quantity shipped, this totals 177,000 to 219,000 metric tons, the original resource. To this might be added 34,000 m3 estimated as a possible (but unseen) deposit beneath Camino los Ceresos, a quantity equivqlent to 39,000 to 62,000 metric tons, again depending on the specific gravity assumed. These estimates, smaller than some others, are based on explorations that indicate the cave systems to be less extensive than formerly believed. Exploitation appears to have worked out completely seven of the eight larger cave systems (Briggs). In summary, about 80 percent of the estimated original deposits of guano have been removed.
Frank H. Wadsworth
San Juan, Puerto Rico