In the March 1912 issue of Popular Mechanics, during the height of airship "balloonacy," one of the world's first aeronautical engineers Victor Lougheed wrote an article arguing that lighter-than-air ships are inferior to the new but rapidly evolving aeroplane. He proved to be right, and his own brothersAllan and Malcolm Lougheedwould go on to found the Lockheed Corporation. Now a part of Lockheed-Martin, the company now manufactures the most advanced aircraft in the world.
The lightest practical aeroplane capable of carrying a man weighs, with operator and enough fuel for flights of reasonable duration, about 1,000 lb. Such aircraft are sustainedas are the birdsby the complex but highly effective dynamic reactions of the air streams flowing under their wings.
The volume of 1,000 lb. of air is about 15,000 cu. ft.the approximate contents of a sphere 30 ft. in diameter. By substituting for this volume of air something weighing less than 1,000 lb., the something weighing less will float statically in the air, just as anything weighing less than water, volume for volume, will float in water,
As a successful flying vehicle, the aeroplane is a development of no more than a very few years. Yet consistently since its advent it has evolved faster than any other device in the history of transportation. Its genuinely utilitarian applications are already considerable. Its applications to warfare are even now a proved success.
Yet the problem of the aeroplane is inherently complex.
The laws governing its action are exceedingly obscure. The limits of its efficiency are still unknown. Its best form is still undetermined. The difficulties of its equilibrium will still take much solving. And at every turn the aeroplane offers a field for investigation that seems as unlimited as it has proved fertile. While its structures are simple and cheap to build, their design is so baffling and involved, so demanding of the finest abilities of the best engineers, as to rank the problem of dynamic flight as one of the most difficult that modern science has to face.
The balloon as a means of travel is still of negligible utility, despite the numerous and long-continued efforts to make use of it in many fields. Without counterpart in nature, it has proved without justification in fact.
Yet the problem of the balloon is inherently simple.
The laws of its action are obvious. The limit of its lifting capacity is the easily ascertained weight of the air. The problems of its propulsion, steering, and navigation are inescapably definite. Yet, in the 50 years the dirigible has existed, it has not undergone a single fundamental change or improvement. Its changes have been changes in detail. Its improvements have been improvements in degree. Although tremendously expensive to build, and almost impossible to keep built, the problems of floating a balloon structure in the air are so inherently simple as to be easily understood by, and thus appeal to the veriest tyros in mechanical science.
Popular Mechanics
Automobile and aviation motor developments have advanced the speed of the dirigible from 7 to a present maximum of some 30 miles an hournowhere enough to make headway against an ordinary adverse wind. Improved fabrics have enabled the dirigible to stay in the air the present maximum of 36 hours, without descending for gas. Similar slight improvements are the most that even its advocates are able to prophesy for the dirigible.
Yet on this much-punctured bubble of fabric-enveloped gas, it is conservatively estimated that there has been expended within the past 60 years most of this within the latter decade of this periodnot less than $50,000,000.
Never elsewhere in engineering history has so great an expenditure been made in a quest for practical results that were in no measure realized. The pyramids may have cost the world more than the balloon, but a definitely practical result was not their object.
Canals have been tremendous consumers of human labor, but canals serve their purpose. Immense sums have been spent in useless and unsuccessful invention, but it requires whole groups rather than single types of worthless devices to total such expenditures as the balloon has achieved.
Airships: A Century Later
Naval and military devicesbattleships, weapons, armor, equipment, etc.are tremendously costly, but these serve the utilities they are designed to serve, however much these types of utilities may be disparaged by peace advocates.
Experiments with dirigible balloons within comparatively recent years have cost, in Germany, $6,300,000; in England, over $2,000,000; in the United States, $4,000,000; in France, $5,000,000; and in other countries of Europe and in Japan not less than $5,000,000 more.
These figures do not include the costly and long-continued experimentation during an earlier period of development, nor do they include the expenditures in non-dirigible ballooning, which has been made a costly hobby to which American and foreign millionaire sportsmen are even yet much addictedapparently under the impression that they are furthering aeronautical research.
The problem of aerial navigation is fundamentally, as the term implies, a problem of navigation of controlled and directed movement from place to place. Only in an incidental way is it a problem of sustention, and to solve the problem of sustention, difficult though it has proved, is not of itself a solution of the problem of navigating definite courses against adverse winds, at sufficient speeds to admit of practical and reasonably dependable travel.
Popular Mechanics
Indeed, by no method of sound reasoning can the term flight be held to apply to mere uncontrolled sustention in and movement through the aira feat that is variously accomplished by projectiles, skyrockets, objects adjacent to exploded dynamite, etc.
Condemned by this analogy, the various phenomena of balloon ascension, drifting, and dirigibilityhowever interesting they may beare by no proper process of logic entitled even to classification with the phenomena of true flight-such as the controlled flight of birds and aeroplanes, faster than the average movement of the earth's atmosphere in the form of winds, such speed and control being absolutely essential prerequisites to any real navigation of the air.
Thus the balloon is an evasion rather than a solution of the real problems of aerial navigation. It floats in the air rather than navigates it, much as a soap bubble may float for a time, and, in reality, is no more a flying machine than a cork in the sea is an ocean liner.
As one authority, writing in a well-known flight magazine, said recently, "We have been experimenting with dirigibles for years, and ... the sum total of success achieved is not a tithe of that attained in the case of the heavier-than-air type in as many months. Another European expert says that Germany "has to thank her dirigibles for her backward position in aviation, but...she has freely and frankly confessed her mistake in pinning her faith to the illusive gas bag.
Popular Mechanics
The fact that numerous flights, so called, have been made with dirigible balloons, and that many of these flights have been widely heralded as being practical instead of merely spectacular, is completely discounted by the further fact that the successes have been, without exception, achieved in almost perfectly calm weather. In all other cases, the result has been complete failure to travel in the intended direction.
The circuitous thousand-mile drift of the recent "transatlantic" Wellman dirigible, over the Atlantic Ocean, is a typical case in point, and instead of being in any way to the credit of the dirigible, as a trip of that distance, constitutes as conclusive proof as could be sought of the completeness with which these gas bags are at the mercy of every wind that blows.
In the course of similar "balloonacy," as these perennial trans-oceanic fiascos have been classed, there is a remote possibility that some fortuitous combination of a good gas bag with a bad chance, may at last result in one of these exploits being crowned by a sufficiently long drift in the right directiona contingency, however, rather more likely to be realized with a good motorless spherical balloon, several of which have already drifted across country to distances substantially equal to the narrowest dimension of the Atlantic Ocean. Then the problem of aerial navigation will be solvedin the daily newspapers.
Similarly, in the case of the great dirigibles of Count Zeppelinwhich unquestionably are far in advance of other constructions of the same general character, and thus constitute a fair measure of the maximum practicability of the dirigiblethe much exploited and sensational "passenger-carrying" trips of these great balloons, in Germany, have not only been conducted in calm weather, but in addition to this have been attended by most frequent accidents and disasters in landing.
Fortunately, these have happened to be without loss of life in most cases, but the property loss in the way of destruction to the giant aircraft has been prodigious. One expert has estimated that there is an average of $10,000 of damage done to the Zeppelin balloons in each three out of every five of the landings they make.
Popular Mechanics
The effect of size on balloon design is a subject that has been befuddled with much misunderstanding. The common assertion that doubling the dimensions of a balloon cubes its capacity, while only squaring the areas of the surfaces, is, of course, true. But it does not follow from this that the lifting capacity increases faster than the weight with increase in size, for to maintain a proportionate strength it is necessary to increase the thickness of the surface material and the weight of the internal bracing, with each added increment of size.
Insuperable objections to the balloon are its inescapably enormous volume and its consequent strict limitation in weight of structure. To ascend, a balloon must be lighter than the volume of air it displaces. And, the weight of a given volume of air being fixed, there is no possible discovery or invention that can open a way of escape from this inexorable factor of the problem. The only substances that even approach air in lightness being also gases, the design of no conceivable lighter-than-air machine can escape the necessity for two essential elementsspace occupied by a gas lighter than air, and a stout envelope of heavier-than-air material to contain the gas. To the weight of these primary essentials must be added the further weight of structure necessary to afford passenger or cargo accommodation.
Since a sphere of air 30 ft. in diameter weighs about 1,000 lb., while a similar sphere of hydrogen, the lightest known gas, weighs only 70 lb., it is evident that the unlikely discovery of a gas lighter than hydrogen can be of no great benefit, for even should it become feasible to encase a vacuum of the requisite size, as some enthusiasts have hoped, this could add to the sustention only to the extent of the eliminated 70 lb. of hydrogen. From all of which it follows that the best of balloons must be hopelessly bulky and fearfully flimsy, and of only the very smallest lifting capacities in proportion to their sizes.
The balloon is an evasion rather than a solution of the real problems of aerial navigation...[it] is no more a flying machine than a cork in the sea is an ocean liner.
Provided with motors and propelling means, they not only oppose the resistance of enormous areas to rapid motion, but also prove of such fragility that their structure must inevitably collapse under the heavy stresses, should sufficient power ever become available-as is not unlikelyto drive them greatly faster than their present maximums of 25 or 30 miles an hour.
In this connection, however, another comparison between the balloon and the aeroplane, relating to the matter of power, is most interesting. An average aeroplane, weighing 1,000 lb., will oppose not more than 25 sq. ft. of projected area to its movement through the air. A balloon of similar lifting capacity, if made spherical, will oppose over 700 sq. ft. to movement through the air28 times as much area as the aeroplane of the same weight.
Even by compacting this necessary bulk into the most approved elongated dirigible form, the cross-sectional area cannot be reduced below a minimum that is still at least six or seven times as great as the area of the equivalent aeroplane. And, since it is area opposed to movement through the air that measures the quantity of horsepower required, it follows that to propel a dirigible against the minimum resistances of its cross section, must forever require much greater power than is required for both the sustention and propulsion of an aeroplane of equivalent loading.
Incidentally, it is to be remarked that all changes from a spherical form, as in realizing or approximating the elongated form of the dirigible, involve special means for staying the structure, in addition to which they add greatly to the area of the envelope required for a given volume of gas enclosed. The problem of weight and structural security are thus greatly complicated.
The most elementary type of balloon is the spherical balloon, designed for mere ascension and flotation in the air, with no attempt at navigation in a lateral direction except as such movement may result from wind.
The invention of the spherical balloon, according to some authorities, is properly to be credited to the Chinese, who, according to the writings of a French missionary, sent up a balloon in celebration of the coronation of a Chinese emperor, in 1306 A.D.
The first European appreciation of the principle by which a balloon is made to ascend appears to have been due to a Jesuit, Francis Lana, who in 1670 proposed an airship sustained by four hollow copper balls, each 25 ft. in diameter. In 1776, Dr. Black, of Edinburgh, made a small balloon that proved to be too heavy for sustention by the hydrogen it contained, but a few years later Tiberius Cavallo succeeded in inflating soap bubbles with hydrogen, with the result that they floated upward until they burst.
The balloon that is commonly credited with being the first was invented by Stephen and Joseph Montgolfier, and sent up from Annonay, France, on June 5, 1783. This balloon was of paper, about 30 ft. in diameter, and was inflated with heated air, affording an ascensional force of probably 500 lb.
Soon after, on August 27, 1783, a hydrogen balloon was sent up from Paris. On September 19, 1783, the brothers Montgolfier sent up a balloon to which a small car was attached, in which were placed a sheep, a cock, and a duck, which thus had thrust upon them the distinction of being the first balloonists.
Popular Mechanics
The descent occurred eight minutes after the start, and the sheep and duck were uninjured. The cock had not fared so well and his condition was gravely attributed by the scientists present to the effects of the thin atmosphere of the upper regions. More recent diagnosis, however, has suggested that he was trampled upon by the sheep.
The first ascent of a man-carrying balloon was ventured by Pilatre de Rozier, proved a complete failure, who went up to a very moderate height in a captive balloon, built by the Montgolfiers, on October 15, 1783. Following this, on November 21, 1783, de Rozier and the Marquis d'Arlandes made the first free-balloon ascension, from Paris, accomplishing a safe descent in a field 5 miles away after about 20 minutes of drifting, at a height of 500 ft.
Since the foregoing, thousands of other balloon ascensions have been made all the world over. In the course of these, some utility has developed in the way of military and meteorological observations, but the early and unavailing attempts to navigate definite courses from one point to another, either in calm weather or independent of the direction of the wind, have not been materially improved upon by the most recent efforts, aided by every resource of modern engineering. Indeed, as one wag has put it, the sole result has been the division of balloons into two classes, "non-dirigibles and neardirigibles."
When it comes to real navigation of the air...nature's model, the bird, is proved by every test of logic and experience to be the only safe pattern for man to follow.
The first obvious line of improvement in the quest for dirigibility was the reduction of the head resistances, as has been already explained. This is the ideal held in view in the many cylindrical, cigar-shaped, and other elongated and pointed gas bags with which the modern student of this subject is familiar.
Dirigible balloons have been developed in three principal typesthe rigid, the semi-rigid, and the non-rigid. Of the first of these, the Zeppelin was the original and still remains the most conspicuous example. In it the whole device is given its form by a maze of internal structure, partitioned into compartments within which the gas is confined in a plurality of small fabric reservoirs.
The semi-rigid type of dirigible, of which the French army has been the chief sponsor, involves a pointed gas bag, not internally braced, and kept in shape by being stayed by netting and numerous ropes to a long truss-like girder beneath it.
The non-rigid balloon is simply a bag kept in shape by its form and the pressure of the gas within it, so it is naturally subject to all sorts of failures to maintain its proper form.
A particular example of the sorry and expensive experiences various governments have had with the dirigible balloon problem is the German government's recent dismissal of the Zeppelin proposition in favor of the aeroplane, for which an army appropriation of some $5,000,000 has been made for the coming year.
Popular Mechanics
Another case is that of the English navy dirigible, aptly dubbed "Mayfly," which recently broke in two and capsized at a total loss of $400,000, the first time it was taken out of the floating shed that housed it.
Further condemnation of the dirigible is found in the fact that most of the ablest engineers who have given attention to its problemsSantos Dumont, Renard, and Ferber, for conspicuous examplesand who have expended vast sums upon its development, with resulting successes that will rank with any, have finally deserted the balloon as hopeless, and turned their attention to the aeroplane.
In the matter of propulsion, experiments commenced with the hand manipulated cars and sails of early investigators and developed down to the engines and propellers of modern dirigibles. So far, however, all successes achieved with dirigible balloons have been more spectacular than practical, and despite the roseate imaginings of popular writers, there is little technical reason for expecting that results of more serious value are in any prospect of attainment,
Even admitting the possibility of an exceedingly limited and precarious utility for the dirigible in warfare, in the opinion of those best qualified to judge, it is most unlikely ever to assume the least importance as a means of travel, and can have no future beyond such as is too often founded upon the activities of ignorant inventors or unscrupulous promoters, or upon the thrills a great dirigible undoubtedly affords as a Gargantuan spectacle.
The cost of gas for each filling of a large balloon is alone enough to place it out of the question for performing commercial travel at reasonable cost. Not less than a thousand dollars worth of hydrogen on the basis of the most economical production possible, is required for each inflation of a Zeppelin balloon, which, though 450 ft. long and nearly 50 ft. in diameter, possesses a reserve carrying capacity of only three or four tons. Moreover, with a century of experimenting, no balloon builder as yet has been able to improve materially upon the first envelopes of varnished silkwhich still remains the most impermeable material and at the present time no dirigible balloon has ever succeeded in staying in the air for more than 36 hours.
The conclusion is inevitable, from any competent and unbiased consideration of both the shortcomings and the merits of the balloon, that it can never really compete with the aeroplane as a practical means of traveling in the air. Mere going up in the air is another matter, but for the uses that can be thus served, the simpler and cheaper spherical balloon would appear to be in every way superior to the expensive and practically no more useful dirigible.
When it comes to real navigation of the air, to fast, certain, and absolutely controlled travel in any desired direction, nature's model, the bird, is proved by every test of logic and experience to be the only safe pattern for man to follow.
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The Fallacy of the Dirigible | !912 Review of Dirigibles - Popular Mechanics
