Smoke. Use of, In an Invasion of Great Britain. Memo. By War Office

N.B. The strength of source is directly proportional to the speed of the wind. The speed of travel of the cloud is equal to the wind speed; the duration of the passage of the cloud over the objective will be equal to the period of emission. 9. The possibility of the admixture of toxic gases to the smoke cloud should not be overlooked. This would not in any way affect its screening properties. 10. The following is an example of how such an attack might be made:In conjunction with an attempted landing on the South Coast of Sussex, in early July, or as a feint attack, a source about 20 miles long might be established between Dieppe and Fecamp, given suitable meteorological conditions and a southerly wind of 15 miles per hour.