Further north, his divisions heavily depleted, and reinforcements coming up only slowly, General Gough abandoned the strong Somme-Tortille line, and continued his retreat westward, towards his reserves in the old battlefield of 1916. The same day, the first French units to arrive were thrown between Crozat Canal and the woods of Genlis and Frières, linking up, on their right, with the 125th Division, detached from the left of the 6th Army, and established astride of the Oise, in front of Viry. (_Sketch below_). The 1st Division of dismounted Cuirassiers (Brécart) vigorously attacked the enemy, and succeeded in staying their thrust towards the Oise. The 9th Division (Gamelin) barred the Ham-Noyon road, along a ten mile front. On their left, the 10th Division (Valdant) held the zone north of Guiscard. [Illustration: _The French Divisions were engaged from the Oise to Nesle, before Noyon, which the British retreat left unprotected._] On the evening of the 23rd, the situation was critical. General Pellé's divisions retarded the German advance in front of the Chauny-Noyon region, which they were covering, but the enemy held Ham. In their retreat, the British constantly bore to the north-west. The 1st Cavalry Division (Rascas), and the 22nd (Capdepont) and 62nd (Margot) Divisions arrived, and were thrown into the battle between Guiscard and Nesle, where they attempted to join hands with the French 10th Division on their right and with the British on their left. [Illustration: _Converging on Noyon, the Germans effected a breach north of Nesle._] The same day, the German long range "Bertha" guns began to bombard Paris, in the hope of spreading panic and disorder there. [Illustration: GENERAL HUMBERT.] On =March 24=, the crushing effect of the German thrust was further accentuated by the arrival of new enemy divisions. Favoured by the fog, which entirely hid the valleys of the Oise and Somme, their advance-guards swept the plain with machine-gun fire, in their search for gaps and weak places in the thin French line. All the attacks converged towards Noyon. At 9 a.m., in the valley of the Oise, the capture of Viry-Noureuil threatened Chauny, whilst in the centre, Villequier-Aumont and Genlis Wood were taken. Overwhelmed by numbers, the Cuirassiers, after firing their last cartridges, fell back on Caillouel Hill. The divisions on the left took up positions south of Guiscard. In spite of the unequal struggle, the fighting spirit of the troops remained admirable. On the left of General Pellé's group, between Nesle and Guiscard, the situation was still more desperate, as, having crossed the Somme, the Germans now greatly intensified their thrust. The depleted British units continued their retreat westward, leaving a gap north of Nesle. The French 22nd Div. was hurriedly despatched towards Nesle, and elements of the 1st Cav. Div. to the east of Chaulnes.