The ancient peoples of Babylon and Egypt have presented us with many valuable scientific and technical innovations. In the fields of arithmetic, geometry and astronomy they made major contributions and in the art of erecting barehanded buildings from huge stone blocks they are unsurpassed to this day. But as far as I know they did not get involved in the theory of gases, nor did they build machines to conquer the sky.
The history of the balloon starts with Greece, where Archimedes (287-212 B.C.) formulated the principles of sinking, rising and floating and Hero (20? A.D.) invented the plunger type water pump. In our own seventeenth century there was Torricelli (1608-1647), who demonstrated the phenomenon of a vacuum by upending a long glass tube filled with mercury and Von Guericke (1602-1686) who adapted Hero’s pump to pump air. In this way he could evacuate his famous Magdeburger Half Spheres and demonstrate the surprising force exerted by the pressure of the column of air above us.
One result of all these experiments with vacuum was that the idea that air had weight became generally accepted.
Magdeburger balls emptied of their inside air were somewhat lighter than air-filled ones. Giovanni Alfonso Borelli (1608-1679, see my previous post), Italian physiologist, mathematician and friend of Galileo, speculated that if one would make very light spheres, for instance out of very thin copper plate and draw all the air from their insides, they would float in the air according to the law of Archimedes. Unfortunately spheres formed out of very thin plate would not be able to withstand the atmospheric pressure from outside and would be flattened by it.
Undaunted by considerations like these the Jesuit father Lana de Terzi (1631-1687), who longed to go to heaven, made the same fatal flaw in his thinking. In his book ‘Prodromo Overo Saggio de Alcune’ of 1670 he describes a true ship of the air, an open gondola lifted by four copper spheres of almost 25 feet diameter that have no air inside. The ship is drawn forward by a span of twelve geese. De Lana was probably the first to be concerned that this invention, like all other man made instruments, could be misused for war. An airship such as this would make war even more brutal and horrifying than de Lana had experienced in his own lifetime. He therefore concluded that God would prevent the construction of this sort weapons. He certainly was he a naive optimist.
Of course his idea of the twelve geese was endearing. In flight it must have looked somewhat like the picture hereafter, which shows the Canadian Joseph Duff flying southward with a flock of cranes that have as much trust in their pilot as de Lana had in his god.
On Sunday July 5th, while enjoying my time at the beach, Daniel Boria, age 26, was floating over the Calgary stampede grounds carried aloft by 110 helium filled balloons while sitting in a lawn chair.
Our fascination with balloons goes back a long time, to Francisco Lana-Terzi [1631-1687] or maybe even earlier, to Giovanni Alfonso Borelli as decribed by that famous science (fiction) writer Isaac Asimov [1920-1992]:
BORELLI, Giovanni Alfonso
Italian mathematician and physiologist
Born: Naples, June 28, 1608
Died: Rome, December 31, 1679
“Borelli was a professor of mathematics and a friend of Galileo. His life, though not characterized by the controversies of his great friend, was not entirely smooth. In 1674 he had to leave Messina, the Sicilian city in which he was then teaching, and retire to Rome, where he remained under the protection of Christina, former queen of Sweden. (This was the queen whose eccentric habits had brought on the death of Descartes [1596-1650]. She abdicted in 1654 and was received into the Roman Catholic Church the following year, after which she settled in Rome.)
Borelli corrected some of Galileo’s overconservation. Galileo [1564-1642] had neglected Kepler’s [1571-1630] elliptical orbits, but now Horrocks [1618-1641] had extended them even to the moon, and Borelli rescued the ellipses, publicizing and popularizing them.
He tried to extend the vague notions of Galileo and Kepler concerning the attractive forces between the sun and the planets, but was not successful. He tried also to account for the motion of Jupiter’s satellites by postulating an attractive force for Jupiter as well as for the sun. In this he (and Horrocks also at about this time) made a tentative step in the direction of universal gravitation, but the theory had to wait a generation for Newton [1642-1726].
Borelli suggested (under pseudonym) that comets travelled in parabolic orbits, passing through the solar system once and never returning. (The parabola, like the ellipse, was first studied by Apollonius [261-190 BC]. A parabola is an open curve something like a hairpin.) Any body following a parabolic path would approach the sun from infinite space, round it, and recede forever. Such an orbit would explain the erratic behavior of comets, without completely disrupting the orderliness of the universe.
Borelli understood the principle of the balloon, pointing out that a hollow copper sphere would be buoyant when evacuated, if it were thin enough, but that it would then collapse under air pressure.
It did not occur to him that collapse could be avoided if a lighter-than-air gas were used to fill the sphere as, in essence, the Montgolfier brothers [1740-1810 and 1745-1799] were to do a century and a half later.”
—————–  Isac Asimov: Biographical Encoclopedia of Science and Technology (chronically ordered); 805 p. Avon Books, 1976
Born: Zalaegerszeg, Hungary, 20 December 1850
Died: Vienna, Austria, 13 January 1897
Timber merchant; airship designer
SCHWARZ, Melanie: his wife and business partner
SCHWARZ, Vera, their daughter; opera singer
A tin airship was brought to flight by David and Melanie Schwarz from Agram, Dalmatia (now Zagreb, Croatia). At the end of the nineteenth century, it was they who built the first metal airship in the world. The story is well documented by now (see links below) but remains remarkable because they were the predecessors of Graf von Zeppelin, who is generally assumed to have been the first to build the historic metal steerable, lighter-than-air vehicles that now carry his name.
It is also remarkable because here a woman played a decisive role in the construction of a flying machine. (In the first half century of aviation history there have been a good number of courageous and successful female pilots, I know, however, of no other example of a woman who was involved in the business of building a flying machine, nor have I ever heard of major contributions in this field by ladies such as Mme Blériot, Mrs. Boeing or Frau Heinkel…)
The husband, David, was a man of some importance, a timber merchant who every year spent long months in the forest, overseeing logging operations. His desire was for a magical, mighty machine that would be able to lift the cumbersome trunks of trees straight up and out of the hilly terrain. His thoughts materialized into the design of a rather large metal cylinder, filled with hydrogen gas. The pressure inside the vessel would equal the outside air, so as to avoid extreme forces on the shell. In order to be able to levitate, the total construction, plus its load, would have to be lighter than the air it displaced, according to the Law of Archimedes.
Being an avid reader of technical books, he had learned of the miraculous metal aluminium (or aluminum in English speaking countries), known since 1825 as silver-from-clay. As Wikipedia states: “Aluminium is the third most abundant element (after oxygen and silicon), and the most abundant metal in the Earth’s crust.” Yet it proved extremely hard to extract from its host, the ore bauxite. Indeed, the first small quantities produced were so costly that they were used only for art objects and expensive cutlery at the court of Napoleon III.
Production on an indutrial scale had to wait until in 1886, when Charles Martin Hall in Ohio, USA, and Paul Héroult in France invented the electrolytic process of refining aluminium at practically the same time, using an electro-oven. This development was only possible after the perfection by George Westinghouse (and predecessors) of the electrical transformer, a device that could deliver to the oven extremely large currents at low voltage. The oven required a vast amount of electric power, which had become available on an industrial scale after Man had learned how to build hydro-electric power stations (for instance at Niagara Falls, 1895 and Neuhausen Switzerland, 1888). The production of relatively cheap aluminum became from then on feasible and Schwarz’s dream came into the realm of reality.
It goes without saying that in order to become truly dirigible, his tin cylinder would also need a motor with propeller and rudder (although for lifting tree trunks out of the woods a cable balloon might have served the purpose). The practical, portable combustion engine was put on the market around 1885 by Gottlieb Daimler and Carl Benz.
Summing up, we may say that the light-weight metal steerable airship could not have been built before 1890 and that Schwarz’s invention represented the cutting edge of technology.
Schwarz first approached the Austria-Hungary War Ministry, but received little interest in his ideas. He found more resonance in Russia and a first attempt by him to build a metal airship was made in St.Petersburg. When these attempts failed Schwarz returned to Zagreb.
In 1894 he got involved with the German entrepreneur Carl Berg from Ludenscheid, Westfalen. Carl’s firm specialized in the production of aluminum flat sheet and rolled shapes with various profiles. The factory obtained raw metal from the first European aluminium smelter in Neuhausen, Switzerland (1888), later known as Alusuisse. Berg saw great potential in Schwarz’s project and decided to help him transform ideas into hard reality. In fact, it was Berg’s engineers who made the definitive calculations and ultimate design for the airship. On paper it looked sort of like a giant spray can lying on its side: a cylinder with a flat bottom and a conical point. An open gondola hanging from the cylinder would hold the pilot, the Daimler engine (16 hp) and the steering controls. Via belts the engine drove no less than four propellers, one of them a horizontal one to aid levitation. According to one account the ship measured 38 meters (125 ft) from tip to tail; its diameter was 12 meters (40 ft). The aluminium skin was 0.2 mm thick (equal to four sheets of kitchen aluminium foil) and riveted air tight on a skeleton of thirteen aluminium hoops and longerons of angle profile. Important: at the highest point of the cylinder was a hydrogen release valve that could be opened from the gondola.
Berg and Schwarz came to the agreement that Berg would assume all further costs. He would produce the parts that were to be assembled under the supervision of Schwarz at Tempelhof Airport in Berlin. It took till the summer of 1896 to get the metal airship ready. Then it was discovered, during the last preparations for the first flight, that the so-called hydrogen gas supplied by a German chemical factory was not of sufficient purity; its specific weight was not low enough in comparison with the air it was displacing and so the loaded airship would not float upwards. Further tests had to be postponed.
To the great dismay of his family and business associates, David Schwarz was hit by a fatal stroke while in Vienna on the 13th of January, 1897. The Jewish community of the city of Vienna gave him a funeral with all due honor and a monument at the Zentralfriedhof of the city.
Carl Berg feared he was now stuck with a bizarre and rather fantastic-looking aluminium cylinder whose inventor and promoter had taken his leave forever. However, high-quality hydrogen gas was delivered in Berlin at that same day and Melanie Schwarz came to the rescue. Contemporary sources state that she was a “delicate yet unbelievably energetic lady”. Apart from caring for her family she had always assisted David in his endeavors. Everybody was surprised when she took charge of the project. The preparations for the first flight were resumed resolutely. She engaged a Mr. Jagels, a military man who had, as he said, some experience in ballooning and who was prepared to wager his life for a modest compensation .
Filled with almost pure hydrogen gas, the tin cylinder finally elevated itself from German soil in the presence of a vast crowd on the 3rd of November, 1897. A hard and cold wind blew from the east. Jagels had practiced ballooning under simple circumstances; now it was demanded of him to observe a multitude of variables such as wind, altitude, obstacles, engine revs and desired course, while at the same time handling the engine, the drive belts and the rudders. The ship did lift off, but thereafter things went wrong. The drive belts jumped from their wheels, the propulsion failed and the little ship was carried off, out of control, by relentless and swirling winds to a height of more than four hundred meters. Caught in a basket and at the mercy of the elements, this height is frightening to even the most obliging person and it is understandable that Jagels did the only thing that he could possibly think of: he yanked hard at the cord that opened the safety valve. Unfortunately, just like Blanchard ninety years earlier, he let too much of the good gas escape. The ship, suddenly having lost its buoyant force, dove down and, zigzagging like a punctured child’s balloon, struck the earth at an oblique angle. Fortunately, the skipper was able to jump just before the metal cylinder flattened the gondola against the ground and so saved his dear life.
Melanie showed a remarkably modern talent for public relations. She dispatched the following telex to Carl Berg:
“HYDROGEN FILLING AND LIFT OFF FULLY SUCCESSFUL” STOP
“SHIP ATTAINED 1000 FT MADE 2 TURNS” STOP
“DRIVE BELT PROBLEM CAUSED PREMATURE LANDING” STOP
“SHIP DAMAGED” STOP
“JAGELS UNHURT“ STOP
“MELANIE SCHWARZ“ STOP
Unfortunately, this diplomatic account of affairs could not withhold Berg from withdrawing from the project. He had the remnants of the ship melted. (One of the curious properties of the new metal was that it could be completely recycled.)
Melanie appeared one more time on the stage of history when a certain Count von Zeppelin approached Carl Berg to embark with him on a new project for a metal airship. “This ship will be completely different. It will have an exo-skeleton of aluminum girders that will be covered by watertight fabric. The gas will be held inside in a row of conventional balloon bags.” Berg was highly interested but felt himself tied by contract to the Schwarz estate. To nullify the obligations, the following proposal was made to the heirs: during a three-year period the Schwarzes would be paid the equivalent of 15,000 Reichsmark, with a royalty of 10,000 Reichsmark for every airship delivered, with a maximum of thirty airships. To their surprise, the generous offer was turned down by the guardian of the Schwarz children, Herr Czillac from Fiume. This male meddling infuriated Melanie and she personally made an appearance at Berg’s headquarters. She was willing to tear up the contract for an immediate payment of 15,000 Reichsmark. “Cash in hand,” she must have reasoned, “that silly old fool Zeppelin won’t ever amount to anything!”
In hindsight, this is a shame, of course, because the thirty airships mentioned in the proposal would already be built by Graf von Zeppelin before 1915, and the previously mentioned three hundred thousand Reichsmark would have been just the sort of money that a mother-alone-with-children could have put to great use.
All together we may safely state that Melanie did well in the end. Her daughter Vera Schwarz(188?-1964) became with dedicated maternal care a famous soprano, appearing in all the major opera houses of Europe and the United States, often together with Richard Tauber. From 1938 to 1948 she lived in exile in the U.S. Upon her return to Vienna she became a sought-after teacher, giving well attended master classes.
In 2011 a street in Vienna’s 23rd district was named Vera-Schwarz-Gasse in her honour.
With some disappointment Carla looked through the downward slanting large windows: there was still nothing more to see than grey fog, a pea soup that seemed to touch the windows and that moved past with considerable speed. Of course she had it wrong, she realized, the ship was moving forward at one hundred twentyfive kilometer per hour and it was the fog that was stationary.
They had departed from Frankfurt yesterday and that had been an exciting experience. The ship had been moored to the landing tower at a height of about thirty meters and hundreds of people had swarmed below it. Commands and shrill whistle signals could be heard, hawsers were cast off, even a ship’s bell was sounded. She had heard a steady discharge of water – that was ballast, she was told. Then the ship had moved slowly away from the mast, going backward and upward in a stately manner, while the crowd below was cheering and waving. She had felt a shudder going through the mighty structure surrounding her, followed by a steady vibration when the engines took hold of the airship and started to propel it forward. The “Hindenburg” had freed itself from the airport departure site and had at first flown low over the city until it had begun to rise gradually into the clouds.
Obviously that’s where they still were at present. Carla had slept very well and after having been awakened by a light knock on the door, she had dressed quickly in order to hasten to the dining room with almost childlike impatience. Coming from the ladies’ rest room on the lower deck, it struck her that the corridor was sloping slightly downward toward the rear and that the ship was rolling and pitching lightly. Much gentler than an ocean liner, but, as she moved towards the tail, the movement became more noticeable. The engines hummed far away, not loudly and not bothersome, but rather emanating a feeling of security.
The breakfast room was empty except for two well-dressed gentlemen, most likely business men on their way to Brazil. As Carla walked past them to the large picture window at port, she smiled and exchanged a friendly “grüß Gott”. She had been hoping for a cheerful sunny morning, but outside there was only grayness. All the same, she peered out intently for some minutes as if to grasp the true meaning of the passing cloud patches.
She could not help overhearing the conversation of the two gentlemen. It also concerned the clouds.
“I think we’ll probably stay in the clouds today as long as possible,” said the larger of the two, a military looking man. “In that way the Captain saves his hydrogen gas. See, we are heavily loaded – the fuel tanks are almost completely full – we are near maximum weight. If we get out over the clouds into the sun, the gas cells will heat, the gas expands to maximum and it could well be that the safety valves will bleed it off. But, see, we can’t afford that – we need all the gas to stay afloat, especially during the night. That’s why we are staying in the clouds now. Do you want some more coffee?”
“There is one more thing that shows that we are heavily loaded: we’re cruising with the nose slightly up. That means the forward speed gives the ship some lift on its hull, just like the wing of an airplane. If we were to fly horizontally, with static buoyancy, we might loose height gradually.”
“We could jettison ballast?”
“Yes, we could, that’s true, but we are at the beginning of the journey and the Capitan must make best use of his resources – we may get into a situation later where he needs the ballast badly. Don’t forget that the ship gets slowly lighter all the time because it uses its fuel. In a while we’ll get to a warm country with a much lighter ship. You wouldn’t want to be in a situation where you couldn’t descend because you were too light, would you now? Or where you kept going higher and higher? Haha!”
Carla felt a bit of a shiver – there was much more involved in this type of travel than she had ever suspected.
“But in that case he would valve off the gas, wouldn’t he?”
“Of course, I was only joking. But the essence is to maintain control of the airship in an optimal way by preserving as much as possible of both gas and ballast. Remember, we can use the resources – fuel, gas and ballast – only once. When they’re gone, they’re gone for ever. That’s to say, until we can land.”
“Same with water?”
“Less so. We can collect rainwater and condensation on the hull and replenish our stores. But that takes time.”
The weather outside cleared somewhat. The pea soup became less dense and wispier. Occasionally there were even clear spaces between the shreds of fog. The men behind her continued with their breakfast and the expert on zeppelin travel volunteered more information:
“On the other hand, of course it is advantageous to fly as high as possible.”
“Because there the air is less dense?”
“Yes, the air is thinner; the ship has less drag. That means less effort to propel it. So we can make the same speed with less fuel, or we can go faster with the same fuel – so we arrive earlier in Rio.”
“So, we should fly as high as possible?”
“Yes, but there are limits. First of all we get trouble breathing. Especially the older passengers may not find it very comfortable at two thousand meter. The engines also will have their problems; they deliver less power per liter of fuel. Then there is the cold, mind you. At two thousand meter it may start to freeze. So the ship has to be heated, for the passengers first of all, and that takes fuel again…”
“Yes, but if there are no clouds at two thousand meters, the sun will heat us. You said just now that the gas would get warm …”
“Indeed, by radiation, but the air temperature is low and the air will have to be heated!”
“What fuel do we use?”
‘Diesel, we have four twelve hundred horse power diesel engines.”
Carla no longer followed the conversation. Typical boy’s talk. Men were awful… They could go on and on about something technical. She was more interested in the clouds. They were unmistakably becoming less and less. Occasionally she could even see a small patch of ocean surface. Ripples in a grey sheet: waves seen from a great height. It was only for a moment that she could see the sea and the thought flashed through her that somebody on a ship could have seen the Hindenburg. She imagined being on a ship underneath an endless cover of clouds and then suddenly in an opening, an airship appears and is gone again immediately. A strange thought. Would there have been somebody, there at sea? Or were they the only ones present in this space: a surreal dining room at five hundred meters, surrounded by clouds? Was she dreaming? Did the sea down there really exist? And had the zeppelin been visible from the sea even if nobody had been there to see it? Was there a reality outside the things that you saw yourself?
Fortunately, at that moment more passengers entered the room and a friendly elderly couple invited her to join them. They talked about their destinations and where they came from and soon the disturbing thoughts were gone.
Luftschiff Zeppelin LZ-129 ‘Hindenburg’ was the largest operational passenger airship between the wars in Germany. It had a length of 800 ft and a diameter of 135 ft. Starting March 1936, it flew a regular airservice between Germany and South (later also North) America, until it was destroyed by fire in May 1937 at Lakehurst, New Jersey, USA. In 1936, 17 round trips were made across the Atlantic, carrying an average of 65 passengers with a crew of 56. In that season the ship flew 192,000 miles, carrying more than 2000 passengers and 160 tons of freight and mail. A westward trip took an averige of 65 hours depending on weather conditions; eastward it took ten hours less. The one way fare to the USA amounted to $400.–.