INFANTRYMEN OF THE FIRST ARMY advancing in the vicinity of Sourdeval against the withdrawing enemy forces. The Canadian First Army advancing southward along the Caen-Falaise road was to join forces with the U. S. troops advancing eastward. The Germans put up a strong defense against the Allied troops advancing to encircle them.] [Illustration: FRANCE AN M 4 MEDIUM TANK, rolling into Dreux, passes a German antitank gun (7.5-cm. Pak. 40). On 14 August the Third Army was ordered to leave sufficient forces to hold Argentan and to take advantage of the enemy’s disorganization by continuing the main advance to the east. Advances were made against Dreux, Chartres, and Orléans. On 15 August Dreux was captured and on 17 August the First Army took over at Argentan. On 18 August the Third Army forces swung north to seize crossings of the Seine River below Paris and to begin the deep encirclement of the German troops south of the river.] [Illustration: FRANCE TWO TYPES OF U. S. TRACKED VEHICLES, each mounting a 105-mm. howitzer. 105-mm. howitzer motor carriage M7 (top); medium tank M4A3 with 105-mm. howitzer (bottom).] [Illustration] [Illustration: FRANCE CONVOY CARRYING GASOLINE ALONG RED BALL HIGHWAY. These are 4–5-ton trucks (tractors) towing 2,000-gallon semitrailers (top). A 12-ton truck towing a 45-ton trailer loaded with ammunition, stops along Red Ball Highway (bottom). With the resistance offered by the retreating enemy at a minimum during this period, fuel was a more vital requisite than ammunition. Approximately a million gallons of gasoline were needed at the front every day to enable the armored columns to maintain their headlong rate of advance.] [Illustration] [Illustration: FRANCE MILITARY POLICEMAN DIRECTS TRAFFIC ON RED BALL HIGHWAY. The three essential supplies were food, ammunition, and gasoline, and to get these to the armored spearheads as quickly as possible a system known as the Red Ball Express was instituted. By this, a circular one-way traffic route was established across France from the beachheads to the fighting zone and back again. All civilian and local military traffic was prohibited the use of the Red Ball Highway, and along it the convoys swept at high speed day and night.] [Illustration: FRANCE RAILROAD EQUIPMENT BEING UNLOADED FROM A SEATRAIN at Cherbourg. Motor convoys could not handle the vast quantities of supplies needed to maintain the Allied fighting forces and it was necessary to supplement these convoys with rail transportation. The first scheduled run was made between Cherbourg and Carentan on 11 July 1944, using mostly salvaged French equipment. As soon as the Cherbourg port facilities were sufficiently restored, equipment was brought over from England and put into service.] [Illustration: FRANCE