This date, according to which the Roman army would have landed on the eve of the day of the full moon, is the more probable, as Cæsar, immediately on his arrival in Britain, made a night march, which would have been impossible in complete darkness. The passage of the sea had taken fifteen hours. In the return, it only took nine hours, since Cæsar started at nine o’clock in the evening (_secunda inita cum solvisset vigilia_), and arrived at Boulogne at daybreak (_prima luce_), which, in the middle of September, is at six o’clock in the morning.[418] The date of his return is nearly fixed by a letter of Cicero, who expresses himself thus: “On the 11th of the Calends of November (17th of October), I received letters from my brother Quintus, and from Cæsar; the expedition was finished, and the hostages delivered. They had made no booty. They had only imposed contributions. The letters, written from the shores of Britain, are dated on the 6th of the Calends of October (21st of September), at the moment of embarking the army, which they are bringing back.”[419] This information accords with the date of the equinox, which fell on the 26th of September, and which, according to the “Commentaries,” was close at hand (_quod equinoctium suberat_). Cæsar had, then, remained in Britain about sixty days. [Sidenote: Presumed Dates of the Second Campaign in Britain.] X. Departure of Cæsar from Lodi[420] May 22. Arrival at the army, in the country of the Belgæ (in 12 days) June 2. Inspection of the fleet and of the winter quarters; junction of the four legions in the country of the Remi, on the Meuse, towards Sedan. From June 2 to June 7. Passage from Sedan to the country of the Treviri (80 kilometres, 3 days), From June 8 to June 10. Occurrences among the Treviri, From June 10 to June 15. Passage from Treviri to Boulogne (330 kil., 12 days) From June 15 to June 26. Delay of 25 days at Boulogne, From June 26 to July 20. Embarkment July 20. Landing July 21. Combat July 22. Cæsar returns to his fleet July 23. Ten days of reparations, From July 24 to August 2. New march against the Britons August 3. Combat August 4. March towards the Thames (from the Little Stour to Sunbury, 140 kilomètres) From August 5 to August 11. March from the Thames to the _oppidum_ of Cassivellaunus, From August 12 to August 15. Time employed in negotiations and receiving hostages (8 days), From August 16 to August 23. Return of Cæsar (in person) towards the sea-coast. The 28th of August, on his arrival at the fleet, he writes to Cicero.--(_Epist. ad Quintum_, III. 1.) August 28.