In the Battle of Amiens on 8 August 1918, the Canadian Army Corps excelled. How did the Allied air corps do? The morning fog prevented take-off before 9 o'clock. Some planes then began laying down smoke screens between tanks and certain German resistance points. Others provided highly ineffectual cover for the Canadian troops by machine-gunning and bombing the Germans. Repeatedly, large numbers of planes tried in vain to blow up bridges on the Somme, especially at Péronne and Python, being used (both then and at night) by numerous German reinforcements, which would slow the Canadian push the following day. Lastly, the air corps would be especially useful during this attack because of its ability to observe enemy positions.