Part 66

He estimated that the channel could be made an average depth of twenty-five feet below low-water mark; that the work could be completed in six years, at a cost of about six million dollars.

Another plan included the removal of these rocks and four others in ten years’ time, at a cost of nine millions of dollars; and he presented another plan, by which some of the middle rocks should remain as they were; and the most serious obstruction, known as Hallett’s Point, could be removed in three years, at a cost of three millions.

[Sidenote: DANGERS OF HALLETT’S POINT.]

Hallett’s Point is the most dangerous obstruction in Hellgate. From shore to shore the distance is about six hundred feet; the reef extends more than three hundred feet from one shore, so that the actual width of the channel is reduced to three hundred feet.

The water boils furiously over this reef, and turns a large part of the tide upon the Gridiron Rock, frequently throwing ships upon it. The process of drilling and blasting was considered too slow and ineffectual, and it was proposed to remove the rock by sinking a shaft upon the shore, undermining the entire reef, leaving pillars to support the rock until the work of undermining was all completed, when, by a single explosion, these pillars could be blown away, the whole reef would fall, and the dangerous obstructions to the commerce of New York would be removed.

One pleasant day, in 1871, I was one of a party to visit the scene of General Newton’s operations. Our party embarked on a small steamer at the Barge Office, and proceeded up the East River, stopping on the way to examine the operations in progress for the removal of what is known as Coenties’ Reef. This reef is about six hundred feet from Pier No. 8, on the East River, and lies directly in the busiest part of the harbor of New York, almost in the track of the ferry boats between New York and Brooklyn, and has always been considered very troublesome and dangerous. Attempts have been made at various times to remove this reef, but none of them were successful until the plan of General Newton was tried. The reef is about 250 feet long, and is 130 feet wide in its broadest part. We found a large scow anchored above the reef, and were politely taken on board. The scow is very broad and heavy, and is firmly anchored, so that ships or steamers that run against it can be very little damaged.

In two or three instances, vessels that have come in collision with the scow have retired considerably damaged, while the large and unwieldy craft, remains unharmed.

As we went on board we were taken to the centre of the scow, where there was a circular well about thirty feet across; and in this well there was a dome, which could be raised and lowered by means of machinery. At the top of the dome there was a “telescope,” twelve feet in diameter, that could be extended or shortened in order to accommodate itself to the condition of the tide. The plan of working was to anchor the scow over the place where the rock was to be drilled, and then to lower the dome until it touched the rock. As soon as one part of it struck the rock, rods were pushed out from the side of the dome to rest upon the reef, and perform the work of feet: they readily adapted themselves to the inequalities of the rock, and as soon as they were fastened in their place the dome was almost immovable.

[Sidenote: DRILLING UNDER WATER.]

Inside the dome there were places for lowering drills, and working them, by means of machinery. The drilling engines were run by steam, and the drills, nine in number, were operated simultaneously; the nine holes that they made were in a circle of about twenty feet in diameter. The drill penetrated the rock from six inches to two feet an hour, according to its hardness. When a round of holes was made, the scow was hauled off, the holes were filled with charges of nitro-glycerine in tin cans, and everything was made ready for a blast.

The work of blasting has to be done very rapidly, for the reason that a diver can only go down to arrange the charges at the period of slack water. Everything is made ready at the turn of the tide, and the very instant that the tide falls the holes are charged.

We were not in time to witness a blast; and on two other occasions, when I went to see an explosion, the performance did not come off; some slight accident had happened, so that the slack water period had passed before everything was ready.

When the round of holes has been charged, the diver goes down. The pump to supply him with air is kept at work; the charges are lowered into the water one after the other, and placed in the holes where they belong. When he has arranged everything, he gives a signal and is drawn above. The boats then back away from the reef sufficiently far to be out of the way of the explosion.

[Sidenote: NITRO-GLYCERINE EXPLOSIONS.]

The nine charges are fired simultaneously by means of electricity. The double wire, insulated with gutta-percha, extends into a small cartridge of powder, which is placed in the top of each charge of nitro-glycerine. The ends of the wire are brought quite near each other, and between them a small slip of platinum is soldered. The current of electricity, passing through the wires, heats this platinum to redness, and sets fire to the powder around it. The powder explodes, and its explosion sets fire to the nitro-glycerine. As the battery which furnishes the electricity is on board the boat, the current is thrown into each pair of wires simultaneously and thus the explosions occur at exactly the same moment.

A column of water shoots up into the air, the rock is torn and broken, and there is a general disturbance of the water all round it: ships and boats are warned, by means of a red flag, to keep at a safe distance. It generally happens that a good many fishes that have been swimming around the rock at the time of the explosion are killed, and rise to the surface; those that are not killed are very much astonished, and swim away with great rapidity.

The experience of a diver going down to arrange the charges is not highly agreeable. If he remains longer than the period of slack water, he finds the current so strong that it almost carries him off his feet; and it frequently becomes necessary for him to be drawn to the surface and abandon his work until the next turn of the tide. Should an explosion occur while he is below, it would be pretty certain to cause his death.

The substance which he handles is not the safest in the world, but the engineers seem to be agreed that it is much better in every way than gunpowder. They say that accidents which have occurred from the use of nitro-glycerine have been caused by careless or ignorant handling, and that many accidents to which powder is liable will not occur with nitro-glycerine.

General Newton explained to us that a few days before our visit a slight accident occurred, which would have proved fatal had they been using powder. At that time they were using fulminating caps instead of electricity; one of the fulminating caps was ignited, and set fire to the charge of powder: the case was broken and the nitro-glycerine was spilled about, but nothing serious happened. Had they been using gunpowder instead, the consequences would have been fatal.

[Sidenote: EFFECTS OF NITRO-GLYCERINE.]

In nearly all the modern blasting operations in the United States, in Europe, and in many other places, nitro-glycerine takes the place of powder; it is much more powerful in its effect, a single charge of it breaking and shattering a rock much more than gunpowder. It has the advantage, too, of extending its force completely to the bottom of the hole, whereas gunpowder very frequently acts only part way down the hole.

My individual experience of nitro-glycerine has not been of the most pleasing character. In 1866 I sailed from New York for San Francisco by way of Panama; when we reached Aspinwall we crossed the Isthmus to take the Pacific steamer at Panama. It was nearly sunset when we climbed up the gangway, and stood upon her deck; an hour later, the tug with our baggage, and with the express freight and mails, came out. I was standing near the gangway when the baggage and express matter came on board, and I think, though I will not be positive about it,—and some of my acquaintances say it is very unlikely,—that I assisted in taking a few of the boxes over the rail. Everything was stowed away, and about ten o’clock at night we steamed down the Bay of Panama, and were on our way to San Francisco. We reached the latter city in safety on a Saturday morning, and I was introduced to a very large number of gentlemen, and most hospitably entertained.

Two or three days later, I was walking up Montgomery Street, and met a friend on his way to lunch at a well-known Club House: I would have accepted his invitation to lunch, only it happened that I had just breakfasted; and, bidding him good morning, or good afternoon, I walked slowly towards the Occidental Hotel. I had been there but a very few minutes before I heard a loud report, which jarred the whole building, and set people flying through all the corridors to ascertain what was the matter. I went out, and walked up the street the way I had come. The office of Wells, Fargo, & Co’s Express was, if I remember correctly, two blocks away from the hotel. It turned out that the explosion which had jarred all that part of the city, was in the office of the Express Company.

[Sidenote: A HORRIBLE ACCIDENT.]

To tell the story briefly, seventeen persons were killed, among them some of my personal friends, and as many more had been wounded. The Club House, where I was very near taking my lunch, had been blown up, and several persons who were sitting at the lunch-table were among the injured.

Among the boxes which had been on the steamer with me from New York to San Francisco, had been passed over the rail of the steamer at Panama, and which I had assisted in handling, there were two cases of nitro-glycerine.

One of these cases had exploded at the express office, its contents not being known, and consequently it had not been carefully handled, and in exploding it had set fire to the other. The force was sufficiently strong to cause a marvellous deal of damage, in and around the express company’s building, to break hundreds, if not thousands, of panes of glass, some of them three or four hundred yards away; and all agreed that if those cases had blown up on our steamer we never would have been heard of afterwards.

“Suppose, now,” said one of my fellow-travellers,—“suppose, now, those cases had exploded when we were taking them in at Panama. Why, the steamer would have gone, one half to the bottom, and the other half up in the air, and some of us might have come down a thousand miles away.”

A week or two after this explosion at San Francisco, there was one quite like it at Aspinwall, doing an amount of damage equal to, if not greater than the explosion at San Francisco. Since that time I have had a wholesome fear of nitro-glycerine, and am always inclined to keep at a respectful distance from it. It may be a very good thing in its way, it may be entirely safe if properly handled, but I greatly prefer that it should not be in my way, and that somebody else should handle it.

[Sidenote: AT HALLETT’S POINT.]

From Coenties’ Reef we went to Hallett’s Point, and were landed under the supervision of the general in charge. We were delivered over to the hands of the superintendent, Mr. Reitheimer, who entertained us very pleasantly, and showed great politeness to the ladies and gentlemen of the party, especially to the ladies. He explained all about the works, and opened a mysterious case. In a very short time our heads were full of tunnels, drifts, headings, drills, champagne, nitro-glycerine, reefs, derricks, pale sherry, and all that sort of thing. He showed us his plans and specifications, and then induced us to step into a wooden box slung at the end of a derrick, and be lowered away into a pit of fifty or sixty feet in depth.

This pit formed a shaft which had been sunk on shore to begin the operations upon the reef. From the shaft a series of tunnels extended very much like one’s outstretched fingers. Between the tunnels there were smaller tunnels, running from one to the other, leaving pillars to support the rock and the water above. A strong dam had been built around the mouth of the pit to prevent the water from flooding it. The tunnels or headings, as they were technically called, had been designated by names instead of numbers. Most of the men working there were Cornish miners, and they seemed not fond of numerical designations. The superintendent originally called the central heading Number One, but it was changed to Farragut Heading. The others in order after it were Madison, Humphrey, Hoffman, Sherman, Jefferson, Grant, McClellan, Franklin, and Jackson.

[Sidenote: UNDER HELLGATE.]

At the center of the reef the highest tunnel was known as Grant Heading. Nine feet of rock was left to form a roof. The rock was not very hard, but full of seams and fissures, through which the water constantly dripped. The narrow seams were closed by blocking, and when a wide seam was struck it had to be closed outside.

In one case the miners came upon a horizontal seam, through which the water poured at the rate of six hundred gallons a minute, and before the flow could be stopped, the miners were standing in three or four feet of water. Bags of clay were kept in readiness on the edge of the coffer-dam, over each heading, so that, whenever a seam was found, it could be closed as quickly as possible.

A large number of men were employed in these headings, drilling holes in the rock, and preparing for the great blast to come. For a long time, hand drills only were used, but the work was greatly facilitated by the introduction of drills operated by means of compressed air.

It was not until September, 1876, that the rocks of the reef were completely “honey-combed.” The process left a roof of rock, supported by piers, which were so perforated as to secure their destruction by the blast. The quantities of explosive materials, finally decided upon by General Newton and his engineers, were estimated as follows:—Dynamite, 25,976 pounds; Vulcan powder, 14,244 pounds; Rend Rock, 9,061 pounds; Dynamite in Primers, 3,500 pounds. Dynamite is simply nitro-glycerine mixed with sand, and the Vulcan and Rend Rock are brands of strongest blasting powder. Connected with the explosive material in each of the sealed canisters was a copper wire, and all these wires were connected with the coil attached to twenty-three powerful electric batteries. Thus, the batteries were connected with each canister, and operated upon each, while each canister was connected with and operated upon all the others. To make all these connections, about twenty-three miles of wire was used. The excavations in the rock were filled with water. It required 47,561 cubic yards to fill them. The water was let in at the rate of 2,000 cubic yards per hour, completing the filling at eight o’clock, Saturday evening, September 23d. Three hundred feet from the rock, General Newton had constructed a bomb-proof building, twelve feet square, in which he placed the batteries. The metallic plates were not submerged in the acids till noon of the next day (Sunday), so that the electricity could not be generated till near the time of the explosion, which had been fixed at 2:50 p. m.

[Sidenote: THE GREAT EXPLOSION.]

Guard boats were stationed on the river to force a suspension of navigation, and the police took up a line along the river front to guard against a too near encroachment by sight-seers. At 2:25 p. m. the first signal gun was fired, and, ten minutes later, a second gun announced the near approach of the dreaded hour. The assembled multitude awaited with breathless interest the last and most important scene in the Hellgate drama. Men and women stood, watches in hand, counting the minutes and seconds, or gazing anxiously across the water to where the great upheaval was to take place. All waited in anxious suspense, and finally, at exactly the appointed time, the tiny finger of little Mary Newton, three years old, guided by the firm hand of her father, pressed the magic key, the shock came, away went Hallett’s Point reef, and the fears of the timid were found to have been totally groundless. The shock was merely a dull, deadened sound, as of distant thunder, and the upheaval was less than might naturally have been expected from firing such an amount of explosives. The water rose up like a wall of many geysers to a height of from sixty to seventy feet. It appeared snow-white, and formed of huge cones which had dome-like terminations. There was so much spray between these cones, however, that the appearance of the water was that of a wall from which great columns stood out in high relief. Suddenly there came out from the eastward a dark cloud of mingled stones and earth, in front of which were huge wooden fragments of the coffer-dam. The roof of the mine seemed to rise to the surface, and then slowly sink to the bed of the river. The water, after receding, was black and discolored, and, after seething and boiling for a few seconds, apparently resumed its natural state. The concussion was slight, and crowds of people remained, in the vain expectation of witnessing something which would be on a more magnificent scale.

It was feared that the blasted rocks would pile up around the sides of the excavation, and form a dangerous temporary obstruction. As a precaution, three massive spar buoys were held in readiness to mark the locality until the work of sounding was finished, and the position of the _débris_ discovered. The United States steamer Cactus on the afternoon of Monday, the 25th, began the work of laying out the buoys. The first sounding was made at a distance of two hundred feet from shore, along an arc around Hallett’s Point and over the exploded mine. Tour after tour was made at greater distances from shore, and with the shaft deeper in the water. Not a rock or obstacle of any kind was encountered during the afternoon. In referring to the record of water found at the different soundings, the number of feet reported may be considered the amount of water at mean or average low tide. When the work of excavation began, the tide-gauge showed four feet of water over the average low water mark. The trial-shaft made the tour unhindered at a depth of sixteen feet, thus demonstrating a safe passage for vessels of such a draft at a point where the day before a giant rock protruded from the water. The last trial was made at three hundred and fifty feet out, and showed a depth of twenty-one feet at low water.

[Sidenote: GENERAL NEWTON’S TRIUMPH.]

General John Newton may be said to have achieved a victory greater than any in war. The 24th of September ought hereafter to be celebrated as the jubilee day of commerce, and the anniversary of the greatest triumph of engineering science in history. The seven years’ toil on Hallett’s Point Reef at Hellgate has culminated in a grand _coup de maître_, which was successful in every detail and in the full accomplishment of all the results expected, and all without a single disaster to human life. Begun upon a carefully matured plan—carried on with the quiet, painstaking persistence of science—the long labor of demolishing the great obstacle to navigation has at last been completed.

LXIII.

THE EARLY HISTORY OF MANKIND.

THE STONE AGE.—PICTURE OF ADAM AND EVE.—HOW EVE CUT THE APPLE.—MINERS OF ANCIENT TIMES.—DISCOVERY OF STONE IMPLEMENTS.—THE INVENTION OF FIRE.—HOW GOLD WAS FOUND.—COPPER AND BRONZE.—THE BRONZE AGE.—IRON AND ITS USES.—MINERAL PRODUCTIONS OF DIFFERENT COUNTRIES.—QUICKSILVER IN SPAIN AND CALIFORNIA.—THE WEALTH OF NEVADA.—ROMANTIC STORY OF THE COMSTOCK LODE.—MINERAL FUTURE OF AMERICA.

The most extensively worked mineral substance at the present day is coal, yet it is the most recent of mineral discoveries. Iron, copper, tin, and nearly all the metals were dug from the earth, and used long before the value of mineral coal was known.

In the earliest days of mankind, tools for various uses were made of wood, bones, or stone. The first tools were undoubtedly of wood, but the material was so perishable in its nature that no specimens from those early days have come down to us. Stone, being a harder substance than wood, and much more durable in its character, rapidly took its place. The period when the human race was in its infancy has been properly classified as the “Age of Stone,” for the reason that man at that time was ignorant of the use of metal. Many implements from the stone age have come down to us, and are found in various parts of the world. In the copper mines on the shores of Lake Superior, many tools have been found which were used by a race long extinct, and of which we have no history.

In opening one of these mines, several years ago, more than a hundred stone axes and wedges were discovered near a large mass of native copper, which had been moved a short distance, and supported upon sticks of timber.

No implements other than those of stone were found, and all of these had been broken in an unsuccessful attempt to cut the mass of copper in two. In various parts of America, Europe, and Asia, stone implements from the early days of the human race are found, and at the present time there are many savage tribes belonging practically to the stone age.

In some islands of the Pacific the people have not yet emerged from what is to us a very remote period. Barbarism under some circumstances may almost be considered perpetual.

The history of the early days of mankind upon the earth is very largely a matter of conjecture: much of it comes from tradition, and much of it from calculation. The great antiquity of the human race is a recognized fact, and geologists have shown that the period of early barbarism may have extended over tens of thousands of years. Civilization, properly speaking, began only with the discovery of fire and metals.

[Sidenote: DISCOVERY OF FIRE.]

Some of the Greek mythologists say that Prometheus stole fire from heaven. The more prosaic fact is, that fire was first discovered by means of lightning, which set fire to the forests, and thus revealed to mankind a new element in nature. It is probable that our first parents in the garden of Eden had no knowledge whatever of this element, or of the metals, or even of implements of wood or stone. Consequently the enthusiastic artist of the middle age, who drew a picture of Adam and Eve standing in front of a fire to warm themselves, and represented Eve holding a knife in her hand, with which she was cutting slices from the fatal apple to give to the waiting Adam, was guilty of anachronism.

There are other conjectures of the discovery of fire, but they are purely conjectures. Fire may have been known from the earliest ages, through volcanic eruptions and streams of lava.

People who lived far away from volcanos may have discovered it from the spontaneous combustion of wood after hot and dry summers, or of masses of weeds and rubbish thrown together, and forming peculiar chemical combinations. It is possible that other people may have discovered fire by means of flint, or they may have obtained it by rubbing two pieces of dried wood against each other, according to the practice of the present day among many savage people.