Fulton's idea for a submarine somewhat resembled the Bushnell design. This is not surprising because a description of Bushnell's invention was published in 1795. By 1797 Fulton had designed his submarine and submitted his plans to the French Directory on 13 December 1797
In a covering letter he said that he was willing to explain his engine to a technical man such as General Napolean Bonaparte, whom he has been told is "a good engineer." Since these propositions formed the basis of all the subsequent negotiations with the Directory, and the government which succeeded it, Here they are presented in full:
CITIZEN DIRECTORS,
Considering the great importance of deminishing the power of the British fleets, I have contemplated the construction of a mechanical Nautilus. A machine which flatters me with much hope of being able to annihilate their Navy; hence feeling confident that practice will bring the apperatus to perfection; The magnitude of the object has excited in me an ardent desire to prove the expirement. For this purpose, and to avoid troubling you with the investigation of a new project, or the expense of carrying it into effect; I have arranged a company who is willing to bear the expense, and undertake the expedition on the following conditions:
First
That the government of France contract to pay the Nautilus Company 400 livres per gun for each British ships over 40 guns which they may destroy; and 2000 livres per gun for all vessels of war under 40 tons which they destroy, that the sum be paid in specie within six months after the distruction of each vessel.
Second
That all prizes of British vessels and cargoes taken by the Nautilus Company; shall be the property of the company; nor meet with any interruption from the agents of government further than to ascertain that they are British property
Third
That the government give to the Nautilus Company the exclusive right to use this invention from all the ports of France, except when it is the desire of government to construct such vessels to act against the enemies of the republic. In such case the government, to be at liberty to build and multiply the mechanical Nautilus, on paying to the company one hundred thousand livers for each Nautilus which they may construct or use in the service of the republic.
Fourth
As a citizen of the American States; I hope it may be stipulated that this invention, or any similar invention, shall not be used by the government of France against the American States, unless the government of America first apply the invention against France.
Fifth
That if peace is concluded with England within three months from the date hereof, government will pay to the Nautilus Company the amount of the expenses which they may have incured in the experiments. Such payment to be made within three months after the declaration of peace.
Sixth
And whereas fire ships or other unusual means of destroying navies are considered contrary to the laws of war, and persons taken in such enterprise are liable to suffer death, it will be an object of safety if the Directory give the Nautilus Company commissions specifying that all persons taken in the Nautilus or submarine expedition shall be treated as Prisoners of War, and in case of violence being offered; the government, will retaliate on the British Prisoners in a four fold degree.
Citizens hoping that this engine will tend to give liberty to the seas; it is of importance that the experiment should be proved as soon as possible in order that if successful the terror of it may spread before the descent on England, and that it may be brought into use to facilitate that descent.
Submitting these proposals to your deliberations and waiting your command, I remain with all possible respect
Your most Obedient ,
Robert Fulton.
NO. 556 RUE DU BACQ.
You will notice that no hint is given in the letter as to the construction of the Nautilus. The propositions were transmitted on 31 Dec. 1797 to the Minister of Marine who generally accepted them with the following amendments to the clauses enumerated;
Fulton accepted the amendments with the exception of clause (5), which he stipulated should read, "the total sum to be reimbursed to the Company on the conclusion of peace should be a sum not exceeding 25,000 francs" the reason given being that the construction and trial of the Nautilus would take three months. Fulton also held to his original demand for commissions for the crew. He proposed to construct his submarine at Paris and test it at Havre. These proposals were submitted to the Minister on the 1St Pluviose on 20 January, 1798.
A draft decree was drawn up and submitted by the Minister to the Directory; but it was never issued, for, on 5 February, 1798 Fulton received from the Minister a letter telling him that all his proposals were rejected. Fulton, however, was not discouraged by this rejection, but took advantage of a change of ministers a few months later to urge once more his invention upon the Directory, this time with rather more success:
Citizens, Not having had the time to busy myself with the drawings and description of the latest changes that I have thought fit to make in my Nautilus, I take the liberty to recommend the model of it to your examination as the best means of enabling you to judge of its form and combinations. Although having exact details of experiments, I shall limit myself to rendering here a succinct account of the most important of them:
First experiment : The Nautilus is 20 feet long and 5 in diameter and according to the calculations of Cen Guyton it will contain a quantity of air sufficient for 3 men and a candle for three hours.
Second experiment : On 24 August, 1800 I plunged in the basin at Havre to the depth of 15 feet having with me two people and a lighted candle; we remained below the surface for the space of one hour without experiencing the slightest inconvenience.
Third experiment : On 25 August I tried to manoeuvre the Nautilus by means of wings 4 feet diameter like the sails of a windmill; to this end at first I placed on the bridge two men with oars; they took 7 minutes to row about 90 toises (192 yards), the length of the basin; then I ordered the same 2 men to set the sails and in 4 minutes the Nautilus covered the 90 toises to the starting place; I proved by this that the speed of sails to that of oars is about 2 to 1 and that these sails are very suitable to manoeuvre a boat under water. The success of this experiment has given me several new ideas which I hope will facilitate much the use of carcasses of powder or torpedoes.
Fourth experiment : On 26 August I tried balancing the Nautilus under water in such a way as to prevent it rising towards the surface or descending to the bottom, meanwhile advancing. This is executed by means of a pair of wings placed horizontally on the front of the Nautilus and which communicate with the interior. By turning these wings from left to right the Nautilus is made to descend below the water, in turning them from right to left, it is raised to the surface. My first trial was unfortunate, in not having placed the boat in the necessary trim in order that the wings could act. The next day I had a decided success and I kept my Nautilus below water at a depth of about 5 feet whilst it covered a distance of 90 toises, about from one end of the basin to the other. This day I made several movements under water and I observed that the Compass acts as well under water as at the surface. The three people who have been my companions during these experiments are so familiarized with the Nautilus and have so much confidence at present in the movements of this machine that they undertake without the least concern these aquatic excursions.
Having thus assured myself of the ease of emersion and of submersion ofthe Nautilus and all its movements as well as the effect on the compass, on 27 August I half filled an ordinary barrel and placed it at anchor in the harbour at about 200 toises (426 yards) from the jetty; I seated myself then in an ordinary boat at the distance of about 80 toises and placed in the sea a torpedo containing about 30 lb. of powder; the torpedo was attached to a small rope of 100 toises; the current going under the barrel, the torpedo passed without touching it; but turning the helm of the boat in which I sat, I made it go obliquely till I saw the torpedo exactly under the barrel; I then drew back the cable till at last the torpedo touched the barrel; at that instant the battery went off, the powder exploded and the barrel was reduced to fragments being lost in a column of water 10 feet in diameter that the explosion threw into the air to the height of 60 or 80 feet.
On 12 September I left Havre for La Hogue and in this little voyage, my Nautilus sometimes did a league and a half (4.5 miles) per hour, and I had the pleasure of seeing it ride the waves like an ordinary boat.
On 15 September I put into a little harbour called Growan near Isigny at 3 leagues from the islands of Marcou. On the 16th the equinoctial gales commenced and lasted 25 days. During the time I tried twice to approach two English brigs which were anchored near one of the islands, but both times, whether by accident or design, they set sail and were quickly at a distance. During one of these trials I remained during the whole of one tide of 6 hours absolutely under water, having for the purpose of taking air only a little tube which could not be perceived at a distance of 200 toises. The weather being bad, I remained 35 days at Growan and seeing that no English vessel returned, and that winter approached, besides my Nautilus not being constructed to resist bad weather, I resolved to return to Paris and place under the eyes of Government the result of my experiments. In the course of these experiments there has come to me a crowd of ideas infinitely more simple than the means that I have employed hitherto and in an enterprise so new and without precedent one ought to expect that new ideas should present themselves, tending to simplify the execution of the great object in view.
As to myself I look upon the most difficult part of the work as done. Navigation under water is an operation whose possibility is proved, and it can be said that a new series of ideas have just been born as to the means for preventing naval wars or rather of hindering them in the future; it is a germ which only demands for its development the encouragement and support of all friends of science, of justice and of society.
Health and respect.
Robert Fulton
PARIS, the 16 Brumaire an 9.