The 51st Division was to capture Beaumont Hamel and push forward between the converging flanks of the 63rd and 2nd Divisions as far as Frankfurt Trench between Glory and Leave Avenues. The 63rd and 2nd Divisions were then to continue the attack, and join their inner flanks east of the 51st Division, thus pinching the latter out of the front line of attack. General Harper was urged to attack with his three infantry brigades in line. He did not, however, consider that an attack launched in such strength and unsupported by a complete unit of reserve was justified. He therefore decided to attack with two brigades in line. It will be seen that the success of the attack and the length of time the Division was able to continue in the line after the attack bears ample testimony to the accuracy of General Harper's judgment in this respect. The 153rd Brigade was detailed to attack on the right, the 152nd Brigade on the left, with the 154th Brigade in reserve. Two distinct objectives for the attack were selected. The first, the Green line, included the Station Road and the village of Beaumont Hamel. The second objective, the Yellow line, was the portion of Frankfurt Trench mentioned above. A further objective east of the Yellow line was given to the 63rd and 2nd Divisions. In the attack on the Green line, three intermediate objectives were selected, known as the Pink line (the German front line), the Blue line (the German second line), the Purple line (the German third line). Each of these lines had a separate wave detailed for its capture composed of units from the following battalions:-- Front line: 7th Gordon Highlanders, 6th Black Watch, 5th Seaforth Highlanders, 8th Argyll and Sutherland Highlanders. Blue line: 7th Gordon Highlanders, 6th Black Watch, 5th Seaforth Highlanders, 8th Argyll and Sutherland Highlanders. Purple line: 7th Gordon Highlanders, 6th Black Watch, 5th Seaforth Highlanders, 8th Argyll and Sutherland Highlanders. Green line: 7th Gordon Highlanders, 6th Black Watch, 6th Seaforth Highlanders (in two waves). The bulk of the machine-guns of the Division were massed in Trench 86 near the Bowery, a small rise in the shape of a tumulus just east of Auchonvillers. From this position an intense barrage was to be fired, moving forward from the German third line through the Green line and across the western slopes of the high ground east of Beaumont Hamel. This barrage was designed to prevent the enemy from using long-range machine-gun fire against the attacking waves, and to hamper the movement of his reserves. In both these respects it proved effective.