The Canadians, on my right, had a similar story to tell; they had driven far into the enemy's defences, exactly as planned. In spite of the difficulties of observation, the recurrence of a ground mist of the same nature as we had experienced at Hamel, and the long distances over which messages and reports had to travel—the stream of information which reached me, by telegraph, telephone, pigeon and aeroplane was so full and ample that I was not left for a moment out of touch with the situation.

The "inwards" messages are, naturally, far too voluminous for reproduction; but a brief selection from the many "outwards" messages telegraphed during that day to the Fourth Army Headquarters, and which, on a point of responsibility, I made it an invariable rule to draft myself, will give some indication of the course of events as they became known:

Sent at 7 a.m.: "Everything going well at 6.45 a.m. Heavy ground mist facilitating our advance, but delaying information. Infantry and Tanks got away punctually. Our attack was a complete surprise. Gailly Village and Accroche Wood captured. Enemy artillery has ceased along my whole front. Flanks Corps apparently doing well."

Sent at 8.30 a.m.: "Although not definitely confirmed, no doubt that our first objective green line captured along whole Corps front including Gailly, Warfusee, Lamotte and whole Cerisy Valley. Many guns and prisoners taken. Infantry and Artillery for second phase moving up to green line."

Sent at 10.55 a.m.: "Fifteenth Battalion has captured Cerisy with 300 prisoners. Advance to red line going well."

Sent at 11.10 a.m.: "Have taken Morcourt and Bayonvillers and many additional prisoners and guns. We are nearing our second objective and have reached it in places. My Cavalry Brigade has passed across our red line. We are now advancing to our final objective blue line."

Sent at 12.15 p.m.: "Hobbs has captured Harbonnières and reached blue line final objective on his whole front."

Sent at 1.15 p.m.: "Australian flag hoisted over Harbonnières at midday to-day. Should be glad if Chief would cable this to our Governor-General on behalf of Australian Corps."

Sent at 2.5 p.m.: "Total Australian casualties through dressing stations up to 12 noon under 600. Prisoners actually counted exceed 4,000. Many more coming in."

Sent at 4.40 p.m.: "Captured enemy Corps H.Q. near Framerville shortly after noon to-day." (This was the 51st German Corps).

Sent at 8 p.m.: "Corps captures will greatly exceed 6,000 prisoners, 100 guns, including heavy and railway guns, thousands of machine guns, a railway train, and hundreds of vehicles and teams of regimental transport. Total casualties for whole Corps will not exceed 1,200."

The vital information, which it is imperative for the Corps Commander to have accurately and rapidly delivered throughout the course of a battle, is that relating to the actual position, at any given moment of time, of our front line troops; showing the locations which they have reached, and whether they are stationary, advancing or retiring. For it has to be remembered that the whole Artillery resources of the Corps were pooled and kept under his own hand; and it was imperative that any changes in the Artillery action or employment must be quickly made, so as to extend the utmost help to any Infantry which might get into difficulties.

Thus, for example, the failure of any body of Infantry to enter and pass beyond a wood or a village, would be a sure indication that such locality was still held in strength by the enemy, and it would be appropriate to "switch" Artillery fire upon it, in order to drive him out. But such a proceeding would be anything but prudent if the information on which such action was to be based were already an hour old.

Transmission of messages from the front line troops to the nearest telephone terminal is usually slow and uncertain, and the retransmission of such messages, in succession, by Battalions, Brigades and Divisions only prolongs the delay. The normal process is in consequence far too dilatory for the exigencies of actual battle control.

A vastly superior method had therefore to be devised, and recourse was had to the use of aeroplanes. The No. 3 Australian Squadron soon acquired great proficiency in this work. They were equipped with two-seater planes, carrying both pilot and observer, and the work was called "Contact Patrol."

The "plane" flying quite low, usually at not more than 500 feet, the observer would mark down by conventional signs on a map the actual positions of our Infantry, of enemy Infantry or other facts of prime importance, and he often had time to scribble a few informative notes also. The "plane" then flew back at top speed to Corps H.Q., and the map, with or without an added report, was dropped in the middle of an adjacent field, wrapped in a weighted streamer of many colours. It was then brought by cyclists into the Staff Office.

Relays of Contact planes were on such service all day on every battle day, and although it was a hazardous duty few planes were lost. The total time which elapsed between the making of the observation at the front line and the arrival of the information in the hands of the Corps Staff was seldom more than ten minutes.

There can be no doubt that the whole operation was a complete surprise both to the troops opposed to us and to the German High Command. It became abundantly clear, in the following days, that no proper arrangements existed for rapidly reinforcing this part of the front in the event of an attack by us, but that these had to be extemporized after the event. This discovery points to the conclusion that the enemy had once again come to regard the British Army as a negligible quantity, a mistake for which he paid an even heavier price than when he made it in the early days of the war.