Show trinidad lake asphalt mining binm BY HAROLD T macfarland As the uses for asphalt increase the importance of natures laboratory far below the earths surface on the island of trinidad british west indies is gaining in appreciation throughout the world the sunbaked sun baked asphalt from the great pitch lake of trinidad discovered by columbus in 1499 and utilized by him for caulking his ships now is filling pressing needs in many countries as a paving material in roofing in paints and as an important component in insulating materials rubber products and other goods natures romance truly is exemplified by trinidada Trini dads asphalt deposit referred to as one of the wonders of the world it may not be a wonder if considered in the same sense as are the pyramids Baby lons hanging gardens and other famous works of bygone centuries but it today ranks as one of the most unusual of natures phenomena and one of her unique and useful gifts to mankind the tropical sun beating down throughout the year on the two great asphalt lakes seasons the bitumen around the deposits palms and other vegetation develop on a scale equalled equal led in few other spots in the western hemisphere tropical birds and butterflies sport their myriads of colors close to the scene of mining operations discovered and named by columbus it was on columbus third trip to america that he visited trinidad As the three peaks of the island rose out of the deep blue of the caribbean sea the hardy spanish explorer bestowed upon atthe it the name it still hears bears in fulfillment of a vow to nanie name the first land sighted in honor of the blessed trinity columbus was the first white man to use the asphalt found in abundant quantities on the shore of the island nearest the lake the legends of the indians the original inhabitants of the island fail to show that the natives made any use of asphalt sir walter raleigh visiting the island a century later caulked caulker several of his leaking vessels with the asphalt at the time recording in his diary that great abundance of stone pitch that all the ships of the world might be therewith laden from thence and we made trial of it in trimming our ship pes raleigh reported that he be found it to be most excellent good and melmeth not with the sun as the pitch of norway trinidad like the other possessions of spain in the new world suffered from conquest from importations of negro slaves and massacres of the gentle mannered indians whose home it had been for centuries before columbus set sail on his first adventure brutalities seldom equalled equal led are recorded in the history of the first few years barber asphalt paving company philadelphia in october mining and oil bulletin of spanish occupation when the search for jewels and gold waxed furious and indians were tortured in an effort to extract news of the supposed hidden wealth became a british possession in 1797 the fertility of the island made it a valuable possession of spain until 1797 when it passed into the hands of great britain it remains one of En glands most valuable holdings in the west indies and the second largest in size although part of the time of spanish possession was not unhappy for trinidad the islands real development came after great britain took possession in recent years the advancement in every line has been almost astounding the former haunts of captain teach better known as blackboard blackbeard and other famous pirates about whose exploits and cruelties cruel ties tales still are told in the west indies have been concerted into busy harbors and trading centers pretentious cities have sprung up great plantations have been placed on a paying basis and the conditions of the residents have been vastly bettered A pitch lake in tropical setting the asphalt lake is located in the center of an extinct mud volcano about twenty eight miles in an air line from port of spain the seat of government and chief city of trinidad it lies on the north side of the southwestern peninsula the point on which the lake is situated apparently being preserved by the bituminous deposits from destruction st by the sea which elsewhere is rapidly wearing away the coast more than tons of asphalt already have been dug from the lake without appreciably diminishing the supply truly raleight Ra leighs prediction that all the ships of the world could be laden was no exaggeration word pictures of the pitch lake painted by imaginative but poorly informed d I 1 writers have depicted a place of intense heat and fetid odors of bubbling liquid and scorched surroundings but such descriptions are far from true the asphalt lake ake itself is a great circular expanse of about acres around it range low hills and on the surface on miniature islands are clumps of stunted trees and low bushes flanking the lake on the inland sides are tropical fore forests ats eap exp expanses an ses of towering palms and other trees and dense underbrush over the lake there is an almost constant breeze welcome indeed to the natives who serve as miners for the temperature usually ranges around 85 and never drops more than 20 degrees below this point the tae asphalt itself is dull bluish gray in color and irregular pools of water dot the surface the term lake may seem a hope less misnomer especially when one refers to pools of water in it but it best describes the great expanse of native pitch folds which in the asphalt take the place of waves in water show that the lake is in constant motion but only by observations extending over days or weeks can this motion be perceived it has been found that the islands themselves change position at irregular intervals ter vals boring to find the depth of the deposit show perhaps better than anything else the slow shifting of the mass recently a drill was forced feet below the surface before the pipes became so twisted by the motion of the asphalt that deeper sounding was impossible origin of deposit depos it various explanations of the origin of asphalt have been advanced but the one now generally accepted by geologists and scientists is that in natures laboratory far below the surface of the earth oil is concentrated and then pushed upward through strata of clay at the bottom of the old mud volcano by the constant pressure from the sides the slow churning action to which the petroleum is subjected in company with the clay mixes the two thoroughly and the result is the asphalt found in the lake and in scattered spots near the great pitch deposit weight is given to this theory by the fact that in comparatively recent years oil strata have been discovered in the neighborhood of the lake many wells have been driven and the production of oil at trinidad now is an import important ani industry composition uniform throughout no variance was found in characteristics between the asphalt at the surface and that extracted by the boring of fee down a striking proof of the thoroughness of the natural mixing process the pitch lake occupies a cone shaped depression and covers a nearly circular area feet above sea level from the lake the ground falls away on all sides except perhaps a slight ridge to the east and southeast the material forming the deposit is an emulsion of water gas bitumen and mineral matter the latter consisting of fine sand and a lesser amount of clay the constant evolution of gas is rc responsible for the motion of the lake according to scientists near the center of the lake the asphalt is softer than along the sides and in several places soft asphalt is oozing up from below this gradually hardens and becomes like the main mass of the deposit the point of evolution moves about from place to place along the lines of least resistance the softer asphalt is in an active state of change and if sealed in a can the gas evolved in a few weeks will break the container an examination of the asphalt shows that it is one of extreme uniformity in compisi tion samples taken from any part of the deposit give the following analysis crude talo dry clo water and gas at degrees C bitumen soluble in cold carbon disulphide bitumen absorbed by mineral water 3 4 0 mineral niini matter on n i ignition g n o n w with it h phosphate 3 water of hydration in clay and silicates 43 61 lom 1000 deposit lay idle until fifty years ago it was not until a half century ago that any real effort to make use of the asphalt from trinidad lake was made prior to that time an attempt had been made to manufacture candles from the asphalt but naturally it failed in 1870 the first successful use of trinidad asphalt for paving was made and immediately a company was organized to mine and transport the material difficulties in getting the crude asphalt from the lake to the shore were encountered the problem of loading it on the ships had to be worked out and the transportation of the material from trinidad to this country and to countries abroad required attention successfully developed by general asphalt company to the solution of the problems various combinations and individuals devoted their attention and they succeeded finally the general asphalt company took over the operation of the industry and now it is on a firmly established efficient basis over the surface of the lake in the form of a great loop extends a narrow gauge railroad laid without ballast the asphalt is solid enough to support the tails rails with their heavily loaded cars for several weeks before they become buried in the asphalt and have to be removed and in a different spot method of mining and handling the asphalt is mined by natives equipped with huge mattocks great lumps of the material weighing 60 or 75 pounds each are flaked from the surface other natives the carriers lift these masses to their heads and carry them to the waiting cars which really are skips on trucks A cable hauls the skips to the edge of the lake where they are fastened to an overhead tram which lifts them and carries them off through the air to the long pier constructed ted to permit the loading of deep draft vessels or to the refinery at brighton where a complete plant has been installed at the pier skips are dumped directly into the holds of steamers where the material soon forms into a solid mass with the result that a repetition of the mining operation must take place when the vessel docks at the big asphalt refinery at maurer new jersey or any other point while the constant mining has lowered the level of the lake several feet it has failed to mar the surface in a general leveling process all signs of excavations are blotted out within a few hours this is due not so much to the fact that fresh asphalt is being pushed up from the lower levels as to the gradual settling of the surface to fill the holes scientists only can guess how rapidly the new new asphalt is being created but the supply in the pitch lake apparently is inexhaustible sim simple p le refining process the refining of trinidad asphalt whether done on the island or in this country is simple and consists only of driving off the water which constitutes about 29 per cent of its weight as dug from the lake and removing sticks and other impurities this is done by heating the material in large tanks lined with coils of steam pipe the asphalt melts and separates from the water after the surface is skimmed to remove impurities the asphalt is run off in barrels and is ready for shipment in the refined asphalt remains all the constituents which are valuable from the chemical or commercial viewpoint there is no boiling above a fire as with heavy oil residues resi dums asphalt used by the romans the use of asphalt dates back to between and 2500 B C it was used by the persians egyptians and babylonians as a cement and preservative and there is evidence that the ancient greeks and romans employed pitch in road building the materials they employed doubtless came from the small asphalt deposits around the dead sea and near the adriatic sea rock asphalt which also is found in limited quantities in kentucky and one or two other states first was used as a road making material in switzerland and its serviceability was discovered only by accident modern asphalt invented in 1870 from wagons loaded with the pitch rock great lumps fell at frequent intervals at the end of several years it was noticed that a highway well nigh perfect as highways e went in the early part of the century had been formed bythe by the grinding of the rocks into fine particles by traffic immediately there was a demand for rock asphalt from all parts of europe but the expense incident to its importation prevented the utilization of this material in america it remained for E J desmedt a belgian chemist to originate or invent the modern asphalt pavement in the united states in 1870 in an effort to imitate the rock asphalt highways of europe he concocted a mixture of sand powdered limestone and trinidad asphalt soften softened ed with the residues from the distillation of petroleum the first efforts were plainly an attempt to get away from the use of coal tar as a cementing material this material having given very disastrous results in washington and other cities the first piece of pavement of any area was laid in front of the city hall in newark N J in 1870 in a rather crude way in 1871 or 1872 another piece was put down in battery park new york and in 1873 a part of fifth avenue new york was surfaced with asphalt incidentally this portion with one or two facings remained in place until 1886 in 1874 or 1875 eighteenth street between fourth avenue and irvn irving 1 place was paved with asphalt as were parts of street and street in new york in these small pieces of work originated the modern asphalt paving industry in america they were sufficiently successful to attract attention and when congress in 1875 76 provided for paving pennsylvania avenue in washington from the capitol to the treasury the commission appointed to determine the most suitable material for the work selected asphalt the work with the trinidad mixture proved successful and serviceable and other cities adopted the pavement many difficulties Difficult iet overcome by SI science fience ence many of these early pavements were very successful while others were most unsatisfactory the builders mixing certain percentages a es of sand pulverized limestone and asphalt cement without any real understanding of why these portions were used except that the mixture was pleasing to the eye of the engineer and could be spread easily and smoothly about 1887 however engineers and chemists began to devote real attention to the problem of asphalt paving great progress has been made until today the industry is on a firmly established basis and science governs the composition of the paving materials te rials as laid on all big operations the proper amount of mineral aggregate the penetration of the asphalt the consistency conss tency of the fluxing flexing material the size of th the e stone atone used all are governed by laboratory tests streets paved with trinidad asphalt have stood the test of service in some ins instances for forty years or more under heavy traffic conditions th the e durability and resilience of asphalt have made it a standard forni form of construction for highways in many cities and states and since the development 0 of f the automobile the demand for such paved highways has increased while the first asphalt pavements naturally were laid in the east its use has spread throughout the country with the trinidad asphalt laid on highways a pavement eighteen feet in width could be constructed around the world londona Lon dons famous tharney victoria embankment and noted streets in ill paris derlin berlin and other european cities have been paved with trinidad as we well city ci Y as main traffic arteries in every large in north and south america broad field of usefulness for asphalt in recent years the application of trini trim dad asphalt to purposes other |