The Phantom of the Poles: William Reed's 1906 Hollow Earth Book

The Phantom of the Poles is a book by William Reed, published in New York in 1906. It argues that the Earth is hollow, that there are huge openings at its northern and southern ends, and that the "poles" explorers had spent decades trying to reach did not exist in the usual sense. Reed thought these ideas explained a long list of strange things that Arctic and Antarctic explorers had reported: long polar nights, odd compass behaviour, the aurora, icebergs, coloured snow, dust on the ice, warm winds and stretches of open water far to the north.

The book's own summary, printed under a cutaway drawing of the globe, puts the idea plainly:

"The earth is hollow. The poles so long sought are but phantoms. There are openings at the northern and southern extremities. In the interior are vast continents, oceans, mountains and rivers. Vegetable and animal life are evident in this new world, and it is probably peopled by races yet unknown to the dwellers upon the earth's exterior."

This article explains what the book says and how Reed argued it. It also places the book in the long "hollow Earth" tradition, from Edmond Halley in the 1690s through John Cleves Symmes Jr. and Cyrus Teed, and shows how polar exploration and geophysics settled the question within a few decades of publication. Hollow Earth ideas are firmly disproven. Even so, Reed's book is worth understanding on its own terms: it was a sincere attempt by an amateur to make sense of real observations, and it shows clearly how a single bold assumption can seem to explain everything.

At a glance

Who was William Reed?

Very little is reliably known about the author. Wikipedia's short entry gives his dates as 1830 to 1920 and describes him as an American writer whose one notable work is The Phantom of the Poles. That entry also states that the book "is considered one of the most influential of the Hollow Earth works", though it is a stub that has been tagged as needing better references since 2014.

The book itself says little about its author. Its title page and copyright notice list Reed together with Walter S. Rockey, whose company published the volume, and it is dedicated to a grandson, Sydney Reed Smith. Reed did not present himself as a scientist or an explorer. He presented himself as a careful reader of other people's expedition reports who had spotted a pattern they had missed. In his General Summary he admits that he may not be a polished writer:

"To conclude that an opinion is worthless because it is not expressed in the best form is a great mistake."

He asks the reader to "give credit to my ideas, rather than my expression." That modest tone runs alongside very confident claims, a combination that appears throughout the book.

What the book set out to do

"A half-score or more of mighty truths"

Reed's introduction states his purpose directly:

"This volume is not written to entertain those who read for amusement, but to establish and prove, so far as proof can be established and proved, a half-score or more of mighty truths hitherto not comprehended."

He saw the whole project as finding one key that would unlock many locks: "one key will unlock them all. Throw away the key, or refuse to use it, and the truths will remain securely locked in the archives of the unknowable." The key was the hollow Earth.

He framed his method as a legal case. He would "furnish the reader with what the lawyers would term a brief, giving authorities on whose statements I base my opinion. The judges, in this case, will be the public." The "authorities" were the explorers whose published books he quoted at length.

The problems Reed listed

The introduction sets out twelve numbered problems. The General Summary that follows works through fourteen. The fourteen in the General Summary are the list most often quoted, including on Wikipedia, and they run as follows in Reed's wording:

1. Why is the earth flattened at the poles?
2. Why have the poles never been reached?
3. Why does the sun not appear for so long a time in winter near the supposed poles?
4. Assuming that the earth is hollow, the interior should be warmer.
5. Does the compass refuse to work when drawing near the supposed poles?
6. Meteors are constantly falling near the supposed poles. Why?
7. What causes the great quantities of dust constantly found in the Arctic Ocean?
8. What produces the Aurora Borealis?
9. Where are icebergs formed, and how?
10. What causes tidal waves?
11. What causes colored snow in the Arctic region?
12. Why are the nights so long in the polar regions?
13. What causes the great ice-pressure in the Arctic Ocean during still tide and calm weather?
14. Why is the ice filled with rock, gravel, and sand?

In the introduction Reed wrote that if he could give "reasonable answers to the above questions—replies that will satisfy any intelligent person—the public will admit, I believe, that I have fulfilled my task." He was sure of himself: "So sure am I that my solutions of the problems given above are correct, I am willing to stake my all on their correctness."

The book's chapters

The 22 chapters take the problems roughly one at a time.

The chapters are mostly long extracts from expedition narratives, with Reed's commentary on how each passage fits his theory. The explorer he quotes most is Fridtjof Nansen, whose account of the Fram expedition, Farthest North, is cited by page number again and again. Adolphus Greely's Three Years of Arctic Service and Louis Bernacchi's account of the Antarctic winter at Cape Adare are also used heavily. A plate near the front shows portraits of "Some Famous Polar Explorers": Kane, Peary, Greely, Sir John Franklin, George W. Melville and Charles F. Hall.

Reed's model of the Earth

Openings, not points

Reed's Earth is a shell with two great openings. A traveller heading north would not reach a point and start going south. Instead the surface would curve gradually downward and around a rim into the interior. Because the curve is gradual, the traveller would not notice the moment of "turning". In Chapter III Reed estimates that "the curve begins" at "probably about 55 to 60 degs. latitude."

In Chapter XXII he gives sizes for the openings. The southern opening, he says, is "fifteen hundred miles in diameter, or forty-five hundred miles in circumference," and the northern one "only one thousand miles in diameter, or three thousand miles in circumference." He explains how he arrived at these figures: the north and south magnetic poles had been reached, "one five hundred miles from the supposed pole, and the other seven hundred and fifty miles," so he doubled each distance to get the width of each opening. In other words, he treated the magnetic poles as lying on the rim of the openings.

Gravity and "the curve"

Reed knew that critics would ask why water and ships would not fall off the edge of the rim. His answer in Chapter IV, "Around the Curve", is that gravity simply holds things to whatever surface they are on, wherever that surface happens to point. He compares the rim to a magnet bent into a circle, which attracts equally on the inside and the outside. In Chapter XX, "The Centre of Gravity", he suggests that if the Earth's shell were about a thousand miles thick, "why should not the centre of the walls be the centre of attraction, as well as of the earth, if solid?" He predicted that "gravity is strongest at the turning point entering the interior of the earth," and that things would weigh less in the interior.

Reed openly admitted that he did not know what gravity is: "Whether gravity is something in the earth that draws, or something in the air or ether that repels, I do not know, nor do I know anyone that does." This is one of the points where his theory is weakest, as later sections show.

What lies inside

Chapter XXII describes Reed's expectations for the interior. He calls this part "speculative," yet he treats the hollowness itself as settled: "It is not like the question, 'Is the earth hollow?' We know that it is, but do not know what will be found in its interior."

He expected:

• Game "of all kinds—tropical and arctic," because the interior would have both warm and cold zones.
• Farmland, "vast territories of arable land for farming purposes," inferred from the pollen he believed coloured Arctic snow.
• Minerals and gems, and perhaps radium.
• "Sea monsters, and possibly the much-talked-of sea serpent."
• Timber, as shown, he said, by driftwood on Arctic shores.
• People. "I also believe that the interior of the earth will be found inhabited. The race or races may be varied, but some at least will be of the Eskimo race, who have found their way in from the exterior."
• A mild climate. "It is about such a climate as San Francisco, I should judge, where one has to stop to think whether it is June or January."

Reed even worked out seasons for the interior. Because the southern opening was wider, he reasoned, sunlight would reach the interior through it for longer, so the inner world would have two summers and two winters in each of our years.

Getting there

Reed treated the trip as a practical engineering problem. In the introduction he claimed that the interior "can be made accessible to mankind with one-fourth the outlay of treasure, time, and life that it cost to build the subway in New York City," and that "the number of people that can find comfortable homes (if it be not already occupied) will be billions."

In Chapter XXII he suggests how to make the voyage. A ship should carry fast auxiliary boats and powerful searchlights. Wireless telegraph stations should be set up "within a few miles of each other" along the route. He also describes his own design for protecting a ship from crushing ice: three to five large timbers of Georgia pine laid across the deck, not fastened to the ship, each made in two pieces joined by large adjustable screws. Near icebergs they could be extended several feet over the side, so that pressure would push them endwise. "Take a small lead pencil, and note its resistance when pressed endwise," he advises. He admitted, "as I am not a shipbuilder there may be objections to it."

The arguments in detail

The heart of the book is a long series of arguments from polar observations. Each follows the same pattern. Reed quotes an explorer describing something puzzling, says that a solid Earth cannot explain it, and says that a hollow Earth explains it easily. The table below sets out his main answers in his own terms, followed by the explanation accepted today.

Flattened poles and long nights

Reed's first argument is that "our school-books teach that the earth is round, and flattened at the poles; but they do not tell us why." He believed that only a hollow Earth could explain it, because "the opening to the interior of the earth would then detract from the roundness just in proportion to the size of the opening." The flattening had in fact been explained by Newtonian physics long before 1906: a spinning, slightly fluid body bulges at its equator. Symmes, the earlier hollow-Earth writer discussed below, actually used centrifugal force to explain the flattening himself.

On polar nights, Reed argued in Chapter II that as a traveller entered the curve, "the entrance to the earth can be represented as a deep valley, and the farther one advances the deeper it becomes." He went further and claimed that "were the earth solid and round, I am of the opinion that the sun could be seen nearly, if not quite, every day in the year." This is incorrect. The long polar night is a direct consequence of the tilt of Earth's axis, and it is predicted precisely by ordinary astronomy.

The compass

Chapter III starts from a real observation. Near the magnetic poles a compass needle that is free to move up and down tilts steeply, and explorers recorded this. Reed wrote that Greely had found a needle hung on an untwisted silk thread "pointing nearly straight up," which, he said, "is just what would be expected if they were nearly at the turning." The steep dip is real. The explanation is that Earth's magnetic field lines run nearly vertically near the magnetic poles. The north magnetic pole is a different place from the geographic North Pole, which is why compasses behave oddly in the high Arctic. Halley had tried to explain the same compass puzzles with his own hollow-Earth model two centuries earlier.

The aurora, meteors and dust

Reed described the aurora as "the reflection of a fire within the interior of the earth." He argued that brilliant colours came from burning volcanoes "containing all kinds of minerals, oils, and so on," while faint auroras came from burning vegetation such as "prairie or forest fires." He tied meteors and dust to the same source. Meteors, he said, were rocks blown into the air by interior volcanoes. Dust found on Arctic ice, which Nansen complained about, had "been analyzed, and found to be carbon and iron, supposed to come out of some volcano."

He attacked a rival explanation, that the dust came from comets, as "most absurd," arguing that comets appear too rarely to supply so much dust. The irony is that meteors really are debris from space. Reed rejected the correct explanation for one phenomenon while offering an incorrect one in its place.

Icebergs and tidal waves

Reed's account of icebergs is one of his most detailed. He believed icebergs formed where interior rivers flowed toward the cold rim and froze at their mouths, layer upon layer, "until, owing to the warm weather in summer, the warmth from the earth, and the warm rains passing down to the sea, the bergs are thawed loose and washed into the ocean." He argued that icebergs "cannot be formed on earth" because a river freezes inland first and thaws at its mouth first.

He then used icebergs to explain tidal waves. "Nothing else can produce one hundredth part of the commotion of a monster iceberg when it plunges into the ocean," he wrote. He dismissed the idea that the Moon drives tides, because such waves "would have to travel more than one thousand miles an hour, which is too fast for a wave of water." In fact the tidal bulge raised by the Moon and Sun does sweep around the oceans at great speed, and tides were well understood in Reed's day.

Warmth, open water and the "water-sky"

Several chapters rest on reports that explorers found milder conditions, open water and plenty of animals at their farthest points north. Reed took these as signs that the travellers had reached the warm rim of the opening. In Chapter XXI he says that explorers had all reached "from 80 to 84 deg. latitude—and all agree that they find it warmer, and with an open sea."

Chapter VI discusses the "water-sky" or "ice-blink", in which the sky over the polar sea reflects the colour of open water or ice below it. Sailors used this effect to find open leads in the ice. Reed believed the mirroring was caused by the polar opening: "The entrance to the interior of the earth is undoubtedly the cause; but how or why, I cannot tell."

Nansen's own drifting expedition plays a large part here. Reed quotes Nansen's frustration at the Fram's slow progress and his remark that "there is no getting over the evidence of that Siberian driftwood." Nansen meant that driftwood from Siberia proved there was a current across the Arctic Ocean, which was the basis of his plan. Reed read the driftwood differently, as timber from forests inside the Earth.

Winds and penguins

Chapter XIX uses Bernacchi's and Peary's reports of steady winds blowing outward from the Antarctic and from Greenland's ice cap. Reed argued: "it comes from the interior of the earth, which accounts for its being warmer, dryer, and always from the same direction." Peary had described the Greenland wind as "invariably radial from the centre outward," which Reed took as air rushing out of an opening. The modern explanation is cold, dense air draining downhill off high ice sheets, known as katabatic wind.

The same chapter includes a picture of an emperor penguin, captioned: "It must migrate for food in winter, but it cannot fly. If the earth is not hollow, where does this bird go when the ice prevents it from swimming?" Emperor penguins breed on Antarctic sea ice through the winter and feed in the surrounding ocean. Reed was right that their life was remarkable but wrong that only a hollow Earth could explain it.

"Cannot reach the poles"

The final argument carries most of the weight. Chapter XXI opens: "That the earth is hollow is proved by the fact that no one can get to the poles." Reed compares the explorer to a man trying to reach the reflection of the Moon in water by rowing toward it: "The moon always keeps some distance away; and so it is with the PHANTOM OF THE POLES." He concludes: "The poles are but phantoms—the earth is hollow, or all principle of reasoning must fail."

In 1906 this argument looked stronger than it does now. No one had yet reached either pole. But it rested entirely on a negative: the poles had not been reached so far. It could be tested, and it was tested within a few years.

Reading the book fairly

It would be easy to dismiss Reed, but it is more useful to look at what he got right and where his reasoning went wrong.

He used real data. Almost every phenomenon he discusses was genuinely reported by explorers: dipping compasses, coloured snow, dust on the ice, rock-laden ice, steady outward winds, the water-sky, driftwood from far away. He quoted his sources with page numbers so readers could check them.

He was open about his method. He said what would count as success: answering the listed questions in a way that would "satisfy any intelligent person." He also said what he did not know, including what gravity is.

But the reasoning had a basic flaw. Reed repeatedly argued that if the Earth were hollow, a phenomenon would occur; the phenomenon does occur; therefore the Earth is hollow. This form of argument cannot prove anything on its own, because many different causes can produce the same effect. The real test is whether the theory makes predictions that other explanations do not, and whether those predictions come true.

He reversed the burden of proof. His closing section says: "The earth is either hollow or it is not. What proof have we concerning the latter? Not one iota, positive or circumstantial." In 1906 there was already a great deal of evidence that the Earth is dense throughout, as the next sections show. Reed did not engage with it.

He often treated "unexplained to me" as "unexplainable". Many of his puzzles, including the flattening of the Earth, polar nights, tides and the dip of the compass needle, already had standard explanations in his time. Others, such as the aurora and coloured snow, were being worked out by scientists in the same years.

His key predictions were clear, and they failed. Reed predicted that no one could reach the poles, and that there were openings 1,000 miles wide in the north and 1,500 miles wide in the south. These were testable claims, and polar travel tested them.

The hollow Earth tradition before Reed

Reed was one voice in a long line of writers who imagined a hollow Earth. Interestingly, his book does not appear to engage with them. In the digitized text the explorers are named again and again, but earlier hollow-Earth theorists such as Halley and Symmes are not. Still, readers in 1906 would have known that the idea was not new.

Myths of the underworld

Stories of worlds beneath the ground are ancient and found across many cultures: the Greek underworld reached through caverns, the Hindu Patala, emergence stories among many Native American peoples, and Dante's Inferno, in which Lucifer's fall opens a funnel in the Earth. These are religious and mythological ideas rather than physical theories, but they kept the image of an inner world alive.

Kircher and Halley

The idea took a more scientific form in the 17th century. Athanasius Kircher's Mundus Subterraneus (1665) speculated about systems of underground cavities and channels of water. The most important early proposal came from the astronomer Edmond Halley in 1692.

Halley started from Isaac Newton's estimate, which turned out to be wrong, that the Moon was denser than the Earth. Rather than accept a dense Moon, Halley suggested the Earth might be partly hollow: an outer shell about 500 miles (800 km) thick, two inner concentric shells and a central core, separated by atmospheres. Each shell had its own magnetic poles and turned at a different speed. Halley proposed this to explain why compass readings changed slowly over time. He imagined the inner regions as luminous and possibly inhabited, and suggested that glowing gas escaping from inside caused the aurora. He remained attached to the idea; his portrait as Astronomer Royal shows him holding a drawing of the Earth's interior as concentric spheres.

Claims that the mathematician Leonhard Euler proposed a hollow Earth with a small interior sun are often repeated, but a scholar of Euler's work, C. Edward Sandifer, found no evidence for them in Euler's writings.

Early tests: Bouguer and Schiehallion

Halley's idea could be tested by measuring how much the Earth weighs, in effect how dense it is. In 1738 the French astronomers Pierre Bouguer and Charles Marie de La Condamine measured how much the volcano Chimborazo in present-day Ecuador pulled a plumb line sideways. Bouguer later wrote that his results at least ruled out the hollow-Earth theory.

A more careful test followed in Scotland. In the summer of 1774, a team led by the Astronomer Royal Nevil Maskelyne measured the tiny deflection of plumb lines caused by the mountain Schiehallion in Perthshire. The mathematician Charles Hutton spent years working out the mountain's volume and presented his calculations to the Royal Society in a hundred-page paper in 1778. The result showed that the Earth's mean density was much greater than that of the mountain's rock. In 1798 Henry Cavendish used a sensitive torsion balance to measure the Earth's density as 5,448 kg per cubic metre, within 1.2 percent of the modern value of 5,515. A largely hollow Earth could not be that dense. By the 19th century, the hollow Earth was no longer a serious scientific hypothesis.

John Cleves Symmes Jr. and "Symmes Holes"

The hollow Earth's most famous champion was an American, John Cleves Symmes Jr. (1780 to 1829), a former army captain who had served in the War of 1812 and then struggled as a trader in St. Louis. On April 10, 1818, he issued his Circular No. 1, which opened:

"I declare the earth is hollow, and habitable within; containing a number of solid concentrick spheres, one within the other, and that it is open at the poles 12 or 16 degrees; I pledge my life in support of this truth, and am ready to explore the hollow, if the world will support and aid me in the undertaking."

He sent five hundred copies to governments, universities, learned societies and members of Congress. The response was mostly ridicule. Symmes's son Americus later wrote that it "was overwhelmed with ridicule as the production of a distempered imagination, or the result of partial insanity."

Symmes kept going. He issued more circulars, wrote newspaper letters and, from 1820, lectured in Cincinnati and other towns using a wooden globe with its polar sections cut away. His original model had five concentric spheres, an outer crust about 1,000 miles thick, an Arctic opening about 4,000 miles wide and an Antarctic opening about 6,000 miles wide. He later simplified it to a single hollow sphere. His most lasting contribution was the idea of polar openings, which came to be called "Symmes Holes". Like Reed, he thought the curve of the rim would be so gentle that travellers could enter the interior without noticing, and he believed this explained erratic compass behaviour in the Arctic.

The painter John James Audubon sketched him in 1820 and wrote on the back: "The man with the hole at the Pole." Symmes died in 1829 in Hamilton, Ohio, where a monument topped by a hollow globe stands in Symmes Park.

Symmes never wrote a book himself. His follower James McBride published Symmes's Theory of Concentric Spheres in 1826. Another follower, Jeremiah N. Reynolds, lectured on the theory and campaigned for a government expedition. The United States Exploring Expedition of 1838 to 1842, often called the Wilkes Expedition, resulted partly from Reynolds's agitation, though he did not sail with it. In 1878 Americus Symmes published a collection of his father's writings to defend his reputation.

Cyrus Teed and the Earth turned inside out

A very different version came from Cyrus Teed (1839 to 1908), a physician from New York State. In 1869, after what he described as a divine revelation during an electrical experiment, he took the name "Koresh" and announced a "Cellular Cosmogony". In Teed's scheme, the Earth is hollow but we live on its inner surface, looking inward. The sky, Sun and stars are all inside the sphere.

Teed founded a religious community, the Koreshan Unity, which practised celibacy and communal ownership. After 1894 its members gathered at Estero, Florida, where they hoped to build a "New Jerusalem". At its peak in the first decade of the 20th century the community had about 250 residents. Teed's followers claimed to have measured the concave curve of the Earth along the Florida coast with a device they called a "rectilineator". Teed died on December 22, 1908. The last member, Hedwig Michel, deeded the remaining land to the State of Florida in 1961, and it is now the Koreshan State Historic Site.

Teed's model is sometimes called the "concave" hollow Earth, in contrast to the "convex" version of Halley, Symmes and Reed, in which people live on the outside.

Other 19th-century voices

Other writers kept the idea in circulation:

• Sir John Leslie, a Scottish physicist, discussed a hollow Earth in his Elements of Natural Philosophy (1829).
• W. F. Lyons published The Hollow Globe in 1868, a Symmes-like scheme that did not credit Symmes.
• William Fairfield Warren, in Paradise Found (1885), argued that humanity began on a lost Arctic continent. This influenced some hollow-Earth writers.
• Fiction used the idea freely. Edgar Allan Poe's "MS. Found in a Bottle" (1833) may echo Symmes, and Nequa, or The Problem of the Ages (1900), an early feminist utopian novel, used Symmes's theory for its setting.

Comparing the models

Reed's version is notable for being relatively simple. Wikipedia's article on the hollow Earth notes that he supported the idea "but without interior shells or the inner sun." He explained the inner world's light by sunlight entering through the openings, which is why he spent time on the interior's seasons.

After Reed: Gardner and later writers

The best-known hollow-Earth book after Reed's is Marshall Gardner's A Journey to the Earth's Interior, first published in 1913 and expanded in 1920. Gardner placed a small sun at the centre of the Earth and built and patented a model of his hollow globe. According to Wikipedia, Gardner did not mention Reed, but he did criticize Symmes.

Later in the 20th century the idea moved further from science and into occultism, conspiracy theories and pulp fiction:

• In 1964 a book titled The Hollow Earth, by "Dr. Raymond Bernard", claimed that flying saucers came from inside the Earth. The writer Martin Gardner (no relation to Marshall Gardner) later revealed that "Bernard" was a pseudonym used by Walter Siegmeister.
• From 1945 to 1949 the science-fiction magazine Amazing Stories, edited by Ray Palmer, promoted "The Shaver Mystery", a series by Richard Sharpe Shaver about a degenerate race living in caves inside the Earth.
• The political scientist Michael Barkun, in A Culture of Conspiracy, distinguishes "hollow earth" ideas, in which most of the planet is empty, from "inner earth" ideas, in which the planet is solid but honeycombed with tunnels.

How polar exploration answered the question

Reed's strongest argument was that the poles could not be reached. Within a few years of his book, explorers began to test that claim directly.

The race to the poles

The dispute over Peary means that 1909 cannot be taken as the clear refutation of Reed. The South Pole is different. Amundsen's arrival on December 14, 1911 is undisputed, and Scott's party reached the same spot 34 days later. Both parties crossed a high, cold ice plateau and reported no rim, no curve and no warmth. The South Pole sits on an ice sheet roughly 2,700 metres thick, at an altitude of about 2,835 metres, some 1,300 km from the nearest open sea.

Flying over the "openings"

Reed's specific numbers made his theory easy to check from the air. If a 1,000-mile-wide opening existed in the north and a 1,500-mile-wide one in the south, any aircraft crossing the poles would have flown over it. The Norge crossed the Arctic from Svalbard to Alaska in 1926, passing over the pole. Byrd flew over the South Pole in 1929. Wikipedia's article on the book sums up: "Subsequent expeditions to and flights over the South Pole have conclusively demonstrated that there are no large holes there."

Since then the poles have been visited by submarine, aircraft, snowmobile and foot. A permanent research station, the Amundsen–Scott South Pole Station, stands at the South Pole. Its geographic marker has to be moved every year because the ice beneath it flows by about 10 metres a year. Satellites now photograph both polar regions continually.

How geophysics answered the question

Even without polar travel, the physics of the Earth had already ruled out Reed's model.

The Earth is too dense to be hollow

As described above, measurements from Schiehallion in 1774 to Cavendish in 1798 showed that the Earth as a whole is about twice as dense as typical surface rock. Today the figures are well established. The average density of the Earth is 5.515 grams per cubic centimetre, while typical surface rocks are about 2.75. If a large part of the Earth were empty, its average density would be far lower than that of its rocks. The only way to match the observed gravity is for the interior to contain much denser material, such as nickel-iron under great pressure.

Reed's suggestion that gravity might be centred in the "walls" of a hollow shell does not work either. Newton had shown that inside a uniform hollow shell the shell's gravity cancels out entirely, so people on the inner surface would not be held to it at all. A hollow shell of rock the size of the Earth would also be unable to support its own weight and would collapse.

Earthquake waves see through the planet

The most direct evidence came from seismology. In 1906, the same year Reed's book appeared, the British geologist Richard Dixon Oldham published the first clear evidence that the Earth has a central core. He found that earthquake waves passing deep through the Earth were delayed in a way that showed a dense core about 0.4 of the Earth's diameter across. In 1936 the Danish seismologist Inge Lehmann showed that the core has a solid inner part surrounded by a liquid outer core.

The time earthquake waves take to travel through and around the Earth directly contradicts a hollow sphere. Seismology shows the Earth is mostly solid rock (crust and mantle), with a liquid nickel-iron outer core and a solid nickel-iron inner core.

Why drilling is not the test

People sometimes point out that no one has drilled very deep. The deepest hole, the Kola Superdeep Borehole, reached about 12 km, while the distance to the Earth's centre is nearly 6,400 km. But the evidence against a hollow Earth does not come from drilling. It comes from gravity, from the Earth's measured mass and density, from earthquake waves, and from direct exploration of the polar regions where the openings were supposed to be.

Why the idea appealed

Reed's book belongs to a particular moment. In 1906 the poles were among the last great blank spaces on the map. Expedition narratives by Nansen, Peary, Greely and others were widely read, and they were full of strangeness: ice that groaned and buckled in calm weather, snow streaked red and black, skies that mirrored the sea, winds that blew warm in midwinter. Some of the science that explains these things was still being developed. A reader who took all the reports together and looked for a single explanation could feel he had found one.

The hollow Earth also offered something emotionally attractive: a whole new world, with land, timber, game and minerals, perhaps even people, waiting just beyond the ice. Reed's promise of homes for "billions" and a journey cheaper than building the New York subway reflects the optimism of his age about exploration and engineering.

Reed's own little parable captures his attitude. He tells of a stranger at Niagara Falls whose friend exclaims, "Isn't it wonderful?" The stranger replies, "I don't see anything to hinder it." Reed applies this to his theory: it "may be surprising, and seem wonderful to many, or ridiculous to others, but I see nothing to hinder it." The flaw is that "nothing to hinder it" is not the same as evidence for it. Science asks for positive evidence that is better explained by one idea than by any other.

Legacy

The Phantom of the Poles is remembered today mainly as a document in the history of fringe science and of the hollow-Earth idea in particular. It is regularly listed among the key hollow-Earth texts alongside Symmes's circulars, Teed's Cellular Cosmogony and Gardner's A Journey to the Earth's Interior. Because it was published in 1906 its text is in the public domain, and scanned copies circulate freely, including on the Internet Archive and sacred-texts.com.

For a modern reader the book has several kinds of value:

• As history of exploration. It gathers long passages from early 20th-century polar narratives and shows how a lay reader of the time responded to them.
• As a study in reasoning. It is a clear example of how a single assumption, once accepted, can be made to fit almost any observation, and why scientists insist on predictions that could prove an idea wrong.
• As a record of a testable claim that was tested. Reed made specific, checkable predictions: that the poles could not be reached and that there were openings of measurable size. Within a quarter of a century, explorers on foot and in aircraft had checked them.

Timeline

Key points

• The Phantom of the Poles (1906) by William Reed argues that the Earth is hollow, with openings about 1,000 miles across in the north and 1,500 miles across in the south.
• Reed built his case from explorers' published reports, chiefly Nansen's, offering a hollow-Earth explanation for the aurora, icebergs, coloured snow, compass dip, polar nights and other phenomena.
• His central argument was that the poles could not be reached. Amundsen reached the South Pole in 1911, and flights over both poles in the 1920s found no openings.
• Gravity measurements from the 18th century onward, and seismology from 1906 onward, show that the Earth is dense and solid throughout, with a metallic core.
• Reed stands in a long tradition that includes Halley, Symmes and Teed. His book is best read today as a sincere but mistaken attempt to explain real observations, and as a clear lesson in how scientific claims are tested.

Sources

• Phantom of the Poles (Wikipedia)
• The Phantom of the Poles, William Reed, 1906: full scanned text (Internet Archive)
• The Phantom of the Poles (sacred-texts.com)
• William Reed (author) (Wikipedia))
• Hollow Earth (Wikipedia)
• John Cleves Symmes Jr. (Wikipedia)
• Cyrus Teed (Wikipedia)
• Edmond Halley (Wikipedia)
• Schiehallion experiment (Wikipedia)
• Richard Dixon Oldham (Wikipedia)
• Inge Lehmann (Wikipedia)
• North Pole (Wikipedia)
• South Pole (Wikipedia)