The Superior Quality and Number of Thaddeus Lowe's Balloons - 1861/1862

Military Ballooning during the Early Civil War, pages 190-191

    On June 26, Whipple notified him that the Topographical Bureau had decided to adopt the balloon for army service, and requested that he submit a full report on his proposed methods of operation, and an estimate of construction costs. Lowe complied at once, not knowing that the Topographical Bureau had negotiated some time before with the Lancaster aeronaut John Wise on the same subject. Much to his disappointment, Lowe learned when he later called on Whipple to ask for a decision, that the Bureau officials had decided to give the order for a government balloon to Wise. The latter aeronaut, Whipple informed Lowe, had submitted an estimate lower by almost $200, but suggested that Lowe might well be employed to operate the new balloon, even though he had not been given the order to build it. Although Wise was senior to Lowe in the profession by more than twenty years, the latter refused to recognize the value of his long experience, and firmly declined to consider the suggestion. "I would not be willing to expose my life and reputation by using so delicate a machine ... made by a person in whom I had no confidence," was his blunt answer. Whipple accordingly considered the matter closed, and employed Wise for service with the army in the coming campaign in Virginia.

Military Ballooning during the Early Civil War, pages 231-238

    At dawn on October 13th the party, exhausted from the night's exertions, reached a point near Lewinsville withing a mile of Smith's headquarters. During the night a stiff breeze had been blowing, and by morning it had increased to a howling gale. Lowe ordered the balloon securely lashed to anchoring stakes, intending to wait until the storm should abate before proceeding on to Smith's camp. Some two hours were spent in making the moorings fast and in keeping the tugging envelope secure, but shortly before six o'clock the tempest reached its height and rendered their efforts useless. "An uncommonly heavy whirlwind swept along," Lowe reported several hours later, "and turned the balloon around like a top, causing the strong cordage to break like pipestems, completely clearing the gas envelope from the network." The free envelope then rose to a high altitude and, taking a northeasterly direction, soon disappeared.

    Two hours later the runaway balloon came to earth on a farm at Laurel, near Seaford, Sussex County, Delaware. The owner of the farm was suspected of being a Southern sympathizer, and since several newspapers later published details of the accident, it was soon established that the stray balloon was the same one that had escaped from McClellan's army. Accordingly several ardent Unionists of the neighborhood demanded that the balloon be given up and restored to the authorities in Washington; and likewise, other neighbors who were Secessionist in sympathy sought to get possession of the envelope in order to destroy it. The Unionists finally secured the balloon and turned it over to John C. Aiken, United States Marshall for that district, who notified the War Department on October 18 that he had the balloon in his custody. Thereupon Assistant Secretary Scott telegraphed Aiken to forward the apparatus to McClellan's headquarters. In the meantime Lowe had learned of the balloon's whereabouts and had instructed John Toy, superintendent of the Assembly Buildings in Philadelphia, where the new balloons were being built, to proceed to Delaware and claim the envelope. Toy took with him an impressive letter of identification and authority, signed by Lowe over the title of "Aeronaut, Commanding Balloon Department, Army of the Potomac." The marshall thereupon disregarded Secretary Scott's instructions and surrendered the balloon to Toy, who brought it to Philadelphia for repairs. The fabric of the envelope was found to be entirely uninjured, despite the rigors of the storm. Only the valve, and the cordage where it had been severed by the wind, had been damaged. These equipages were replaced and the envelope was given a fresh coat of varnish, thus restoring the Union to excellent condition.

    Lowe, now free from further interruption, continued work on the new balloons. the first of the four was completed about the first of November and was shipped to Washington along with the newly overhauled Union. The remaining three were finished about a week later, and the press announced that "Professor Lowe has completed his contract for five balloons, to be used for observatory purposes. The increase in aeronautic apparatus fostered by Porter and McClellan did not end with the completion of this materiel. Some three weeks later, after the new aerostats had been placed in service at various points along the Potomac lines, and after McClellan had ordered one sent to General Thomas W. Sherman at Port Royal, South Carolina, Lowe requested permission to build still two more balloons of smaller size, declaring that the interests of the new branch of the service required this additional equipment immediately. After a short delay, McClellan approved the request, and the two extra aerostats were completed shortly after the first of January, 1862. Thus at the turn of the year the equipment under Lowe's direction included seven balloons of varying sizes and capacities.

    All the new aerostats were similar in construction to Lowe's first government balloon built during the previous August. Fawn-colored india silk, of the type commonly called "pongee," sewn in double thickness, was used throughout in the envelopes. In the Union, fifty-nine bolts of fabric, comprising approximately 1,200 yards, were expended in construction, which had required the labor of fifty seamstresses to complete. The large gas bags consisted of segments of fabric cut from carefully designed patterns, in principle not unlike those employed by a dressmaker. These segments, which somewhat resembled sections of a carefully peeled orange rind, were finished with tapering, biased sides, and were joined with reinforced seams to form the spherical and pear-shaped envelopes of the assembled balloons. In the top of each envelope was fitted a valve, constructed of mahogany with fittings of brass and operated by india rubber springs, carefully cemented into the fabric, which was strengthened by several additional folds at this point of particular strain. The valve shutter and the flanges that received it when closed were treated with a substance called valve cement, prepared from a special mixture of beeswax, brown soap, mutton tallow, and paraffin. The lower part of the envelopes terminated into small, tapering "necks," or appendices, not unlike the trunk of an elephant in shape. These appendices were left open at all times to provide for the escape of gas which might expand to excessive pressure as a result of increased temperatures and also allowed the escape of any moisture that might form within the envelope. Since the gas always expanded upward and outward, the open appendix did not allow the lifting vapor to escape except when the envelope was filled to capacity. The section, where the strain was greatest, was reinforced with extra thicknesses of fabric. A control cord for opening the valve passed through the center of the envelope and, issuing from the open appendix, was loosely attached to the netting hoop, within easy reach of the aeronaut.

    To insure the retention of gas and for protection against weather, the fabric of the envelopes was treated with a varnish made from raw linseed oil, benzine, and japan drier. The oil was first boiled over a slow fire until it approached the consistency of gum, benzine and japan drier being added to thin the oil and render it applicable with a brush. The envelopes were thoroughly coated on the outside with the varnish and allowed to dry, after which they were turned inside out and treated on the interior surface with neat's-foot oil to render the fabric soft and pliable. Altogether four coats of exterior varnish were applied to the new balloons before they were commissioned into service, and the effects of sun, rain, and frost frequently necessitated revarnishing in the field. The chief function of the varnish was to render the fabric gas-tight. It added no tensile strength to the silk, nor did it increase or preserve elasticity, although Lowe referred to the preparation he used as "elastic balloon varnish."

    The cordage and rigging consisted of an enveloping network of strong "linen balloon cord" woven into meshes of diamond pattern, reinforced with drawn knots. The whole netting fitted over the envelope and was drawn together just below the appendix, where it terminated in a series of cords attached to a stout ring, technically called a concentration hoop. The cordage originally employed with the Union had been designed to withstand a strain of ten tons, but after the accident at Lewinsville Lowe equipped all his balloons with rigging capable of resisting a twenty-five-ton stress.

    The wicker car, or basket, was attached to the concentration hoop by a number of strong ropes, which were kept free from interfering with the aeronaut or observer by a second spreading, or stay hoop, placed below the concentration ring. The cars, constructed of willow or rattan, varied in size from small baskets accommodating only one observer, to larger ones capable of carrying four or five men. The dimensions of one of the smaller baskets is given in one of Lowe's dispatches as five feet by three, and two feet deep.

    The control cables for captive ascensions and for towing the inflated  balloons during marches were of strong manilla rope, varying in length up to 5,000 feet. Lowe made it a rule to employ not less than three cables during ascensions, and  sometimes used four when conditions called for added security.  Attached to the concentration hoop, they distributed the strain of the buoyant envelope evenly throughout the netting, thus  assuring all reasonable safety during ascension. These ascension ropes, as they were technically called, were equipped with  pulley blocks of tough lignum vitae, for the paying out and recovery of the cables as the balloon was allowed to rise or  was lowered by the ground crew. Some of the pulleys were of  the snatch block type, for checking the ropes when the desired altitude had been attained. The ropes were controlled by hand through the pulley blocks, which were often attached to trees, and the  ground crew was split into several groups operating like tug-of-war teams, each handling a single cable.

    In size and lifting power the several balloons varied  considerably. The largest of the seven were the Union  and her sister aerostat, Intrepid, each of 32,000 cubic-foot gas capacity and a normal lifting power of four cables and five men. In very favorable weather,  when the envelopes could be fully inflated, this lifting power was doubled at ordinary altitudes. Next in size were the Constitution and the United States, not  so large or powerful as those of the Intrepid class, yet capable of lifting three men and four ropes as a normal load. Their capacity was rated as 25,000 cubic feet.  The Washington was next in order,  containing 20,000 cubic feet when fully inflated, and normally raised a load of two men and four ascension ropes. The latest additions to the corps, the two balloons built in December, 1861, were the smallest to be commissioned into service. Known as the Eagle and the Excelsior, they had envelopes of only 15,000-foot capacity, less than half of those of the Intrepid class. Their normal lifting power was one man and four cables. Like the aerostats of the largest type, the envelopes were filled to capacity, and such maximum inflation could be done only in calm weather.