Note.–The former boundary between the St. Quentin and Laon sectors has been produced along the valley of the river Oise to its junction with the Ailette. A complete list of the units known to be available in the new St. Quentin sector will be published in to-morrow's Summary.

2.    AERODROMES.

(a) New aerodromes:–

3.

ENEMY'S STRENGTH SOUTH OF THE SOMME.
A list (dated 10-4-18) of units on the southern battle front was found on an observer captured by the French on the 15th April (see para. 1 – Identifications). These flights are probably in the Ham area, as several of the units given in the list had lately been identified in that district.
       The identifications given in para. 1 represent an increase of the enemy's strength in aircraft units on the Somme battle front of 3 pursuit flights (2 new formation, 1 from Italy, and 3 reconnaissance and "A" flights (1 from Italy, 1 from Russia and 1 from Verdun).

ARMY AIRCRAFT PARKS.
A recently captured mechanic states that army aircraft parks generally detach an advanced stores depot (Parkstaffel) where spare propellers, a certain amount of rigging material, and engine spares are kept.
       In the case of the Eighteenth Army, the Parkstaffel, when the Park was at Berlaimont, was located at Guise; on the latter moving to Guise, the advanced depot went forward to Ham.

REPLACEMENT AND QUALITY OF MATERIAL.
The same prisoner states that machines are often unserviceable for a week, owing to the lack of spare parts; propellers especially are difficult to procure, and the prisoner states that his flight having applied to the stores depot for 10 propellers, had to wait 4 days, when eventually 3 were issued.
       The quality of material, especially as regards engines, he states, leaves much to be desired.

GERMAN AEROPLANES.
Fokker biplane. (See Summary of Air Intelligence, Serial No. 51).
       Information has been received from the French that this machine is fitted with 3 machine guns, two of which fire through the propeller.
Halberstadt two-seater.
       It is reported by a prisoner that this machine has a slight backward stagger.

GERMAN AIRMEN.
Lieut. Hess, who was credited with 17 air victories, was killed in January last. (German Press).
Lieut. Geigel, reputed to have shot down 15 machines, has been killed. (German Press).

EFFECT ON GERMAN MORAL (sic) OF THE ENEMY'S AIR POLICY.
On the 17th April, an officer Stellvertreter of the 4th Ersatz Division (captured on the 18th), attended a conference at the Regimental H.Q. of the 201st Res. Inf. Regt. to discuss the question of co-operation between infantry and aeroplanes. Numerous complaints were brought forward by the infantry that aeroplanes never appeared to be on the spot when they were wanted, and that the German artillery were consequently unable to locate the enemy.
       The Regimental Commander of the 201st Res. Inf. Regt. stated that they would have saved 1,000 casualties, at least, in the attack on Locon, if they had only had an aeroplane.
       Note.–From the above, it would appear that owing to the absence of aeroplanes, the German gunners have been causing heavy casualties to their own infantry.