[An example given is the destruction of Yuan Shao’s wagons and impedimenta by Ts’ao Ts’ao in 200 A.D.] the fourth is to burn arsenals and magazines; [Tu Mu says that the things contained in "arsenals" and "magazines" are the same. He specifies weapons and other implements, bullion and clothing. Cf. VII. § 11.] the fifth is to hurl dropping fire amongst the enemy. [Tu Yu says in the _T’ung Tien:_ "To drop fire into the enemy’s camp. The method by which this may be done is to set the tips of arrows alight by dipping them into a brazier, and then shoot them from powerful crossbows into the enemy’s lines."] 2. In order to carry out an attack, we must have means available. [T’sao Kung thinks that "traitors in the enemy’s camp" are referred to. But Ch’en Hao is more likely to be right in saying: "We must have favourable circumstances in general, not merely traitors to help us." Chia Lin says: "We must avail ourselves of wind and dry weather."] the material for raising fire should always be kept in readiness. [Tu Mu suggests as material for making fire: "dry vegetable matter, reeds, brushwood, straw, grease, oil, etc." Here we have the material cause. Chang Yu says: "vessels for hoarding fire, stuff for lighting fires."] 3. There is a proper season for making attacks with fire, and special days for starting a conflagration. 4. The proper season is when the weather is very dry; the special days are those when the moon is in the constellations of the Sieve, the Wall, the Wing or the Cross-bar; [These are, respectively, the 7th, 14th, 27th, and 28th of the Twenty-eight Stellar Mansions, corresponding roughly to Sagittarius, Pegasus, Crater and Corvus.] for these four are all days of rising wind. 5. In attacking with fire, one should be prepared to meet five possible developments: 6. (1) When fire breaks out inside the enemy’s camp, respond at once with an attack from without. 7. (2) If there is an outbreak of fire, but the enemy’s soldiers remain quiet, bide your time and do not attack. [The prime object of attacking with fire is to throw the enemy into confusion. If this effect is not produced, it means that the enemy is ready to receive us. Hence the necessity for caution.] 8. (3) When the force of the flames has reached its height, follow it up with an attack, if that is practicable; if not, stay where you are. [Ts’ao Kung says: "If you see a possible way, advance; but if you find the difficulties too great, retire."] 9. (4) If it is possible to make an assault with fire from without, do not wait for it to break out within, but deliver your attack at a favourable moment.