When the before-mentioned proposal was conveyed to Crillon he peremptorily refused to accede to it. Nor could any decision be arrived at regarding the most proper point of attack; the Old Mole, which at first appeared the weakest part of the fortress, was found to be covered by the guns of the principal batteries on the Rock, while the New Mole presented even greater difficulties. There was another matter too which became the subject of discussion up to the very moment of the attack, and this was whether it would not be expedient to supply each floating battery with warp-anchors and the double cables, that they might withdraw in case of accident.
These unfortunate disputes, which arose at a time when perfect unanimity was most essential, hampered the progress of operations, and destroyed that harmony which should have existed between Crillon and his subordinates. D'Arçon especially was offended and annoyed; he claimed for himself the merit of having invented the machines which were to annihilate the place, and insisted upon his right to have the sole direction of their movements. Crillon, on the other hand, perceived that if the command were divided, and the attack should prove successful, the glory of the triumph would be appropriated by the French engineer. In the many councils of war that preceded the bombardment the Duke did not care to conceal his jealousy of the Chevalier d'Arçon. On one occasion, deriding the propositions of the engineer, he exclaimed: "You have a fatherly love for your batteries, and are only anxious for their preservation. Should the enemy attempt to take possession of them, I will burn them before his face." On another occasion, when in the presence of the French princes, he said: "You were summoned into Spain to execute my plan for the attack of Gibraltar by floating batteries. Your commission is performed: the rest belongs to me."
While these discussions and misunderstandings were distracting the councils of the besiegers, a master hand was guiding the preparations for the defence within the fortress. Every emergency that might occur was provided for, every danger that could be foreseen averted, and the garrison itself reënforced by a marine brigade of six hundred men under command of Brigadier Curtis. In the first week of September the land works of the enemy had progressed with gigantic strides, immense batteries, some containing as many as sixty-four guns, only waited to be unmasked, and long strings of mules streamed hourly into the trenches, laden with shot, shell, and ammunition.
The advanced works were not, except in some instances, yet armed, and large masses of material which had accumulated in their vicinity cumbered the embrasures and rendered their parapets liable to destruction by fire. Seizing upon the opportunity thus afforded by the negligence of the Spaniards, General Boyd wrote to the governor recommending the use of red-hot shot against these works. Though the distance was great, and the effect of heated shot had not then been thoroughly ascertained, Eliot acquiesced in the proposition, and Major Lewis, commanding the artillery, was ordered to execute the attack.
On September 8th the preparations were completed, and at 7 a.m. the guards having been relieved, a tremendous fire was opened from all the northern batteries. Throughout the day this fiery cannonade was kept up with unabated fury. By 10 a.m. the Mahon battery and another work of two guns were in flames and by five in the evening were entirely consumed, with all their gun-carriages, platforms, and magazines. The effect of the red-hot shot exceeded the most sanguine expectations; the damage done was extensive and for a time irreparable; the greater part of the communication to the eastern parallel was destroyed, and the batteries of St. Carlos and St. Martin so much injured that they were no longer serviceable. At one moment the works were on fire in fifty places, and the flames, lifted by the wind, spread with terrible rapidity; but by the prodigious exertions of the enemy's troops, who, notwithstanding the galling fire from the garrison to which they were exposed, displayed a reckless intrepidity, the work of destruction was arrested and many of the batteries saved from ruin. Irritated at this unexpected attack upon works which had cost him so much labor and anxiety, Crillon was precipitated into a premature bombardment, which, while it exposed to view the hitherto masked batteries, and thus gave General Eliot an opportunity of preparing counter-works upon the Rock, at the same time did considerable damage to the unfinished lines.
On the morning of September 9th a battery of sixty-four guns opened at daybreak and a tremendous discharge from one hundred seventy pieces of cannon announced the commencement of the final bombardment. At the same time a squadron of seven Spanish and two French line-of-battle ships got under way at Orange Grove, and, dropping slowly past the sea-line wall, delivered several broadsides against the south bastion and Ragged Staff, until they arrived off Europa. Then, having first formed line to eastward of the Rock, they attacked the batteries from the Point as far as the New Mole, with some energy. On the following day this manœuvre was repeated, and the cannonade from the lines was renewed with all its fierceness, six thousand five hundred shot and two thousand eighty shell being thrown into the fortress every twenty-four hours. Notwithstanding this overwhelming fire the loss in the garrison was exceedingly small.
On the 12th the combined fleets of Spain and France, numbering thirty-nine ships of the line, entered the Bay of Algeciras, and having formed a junction with the squadron already at anchor, raised the naval force to fifty ships of the line and two second-rates; nine vessels bore an admiral's flag.
General Eliot was conscious that the hour of trial approached, and so ably had he conducted his preparations that during the twenty-four hours preceding the attack not a single alteration had to be made, even in the most minute directions that had been given to the troops. Every man knew his place, each gun was told off for one particular duty, simple and efficient arrangements had been made for a constant supply of ammunition, and every bastion was furnished with its fuel and furnace for the dreaded red-hot shot.
It was during the morning of the 12th that the governor received information that the combined attack would commence on the following day. Calmly as this courageous man awaited the hour of trial, he could not but be influenced by the gravest anxiety for the result. He had witnessed the gigantic armaments that were preparing for the assault; and though ignorant of the exact force which was to be brought against him, he was aware that neither France nor Spain had spared labor or expense to accumulate a strength hitherto unknown in the history of sieges. On the land he was threatened by two hundred forty-six pieces of cannon, mortars, and howitzers, and an army of near forty thousand men; while by sea fifty sail of the line, ten floating batteries, of a construction supposed to be indestructible, with countless gun- and mortar-boats, and three hundred smaller craft were waiting only the signal for the attack. To this enormous armament, but seven thousand men and ninety-six guns could be opposed. At a council of war held in the Spanish camp on September 4th the final details for the arrangement of the grand attack had been settled, and it was decided to open the bombardment on the 13th of the month.
At this council M. d'Arçon vehemently protested against the precipitate haste with which the preparations of the floating batteries had been hurried on, and vainly pleaded for a few days' further delay, in order that some experiments might be made upon the vessels, and especially that the effectiveness of the water apparatus might be tested. His arguments were met by others equally cogent. Lord Howe with a powerful fleet was known to be on his way to relieve the fortress, and it was of vital importance that his arrival should be anticipated. The season was already far advanced, and the works on the land side, which had only just been repaired, were at any moment exposed to a second partial destruction by red-hot shot. All objections, therefore, were overruled, and the day was named.