History of the 151st field artillery, Rainbow Division, by Louis L. Collins, lieutenant governor of Minnesota. Edited by Wayne E. Stevens, PH. D. Pub. by the Minnesota War records commission.

262 HISTORY OF THE 151ST FIELD ARTILLERY

4. The officers detailed as observers at the O.P.'s above named will make
a thorough study of the enemy terrain in the Divisional sector before the day D.
In order that the enemy's attention may not be attracted to the location of the
O.P.'s, this observation will be made from trenches York and Wilson, from
which the views are practically the same. All activity visible to the enemy in
the vicinity of the O.P.'s in Lufbery Trench will be carefully avoided before
the day D. No observation will be undertaken from this vicinity, and wiring
parties working in the neighborhood will remain carefully under cover.
5. The O.P.'s above mentioned will be used as forward message centers
during the advance of the infantry and runners sent back from D.O.L.'s will
bring their messages thereto. For this purpose all runners will reconnoitre the
approaches to and location of Lufbery Trench.
6. Regimental and battalion commanders may establish such other O.P.'s
as they see fit in trenches York or Wilson on the northern edge of the Bois
du Jury.
IV. PLAN OF LIAISON
1. Telephonic liaison as shown in separate sketch will be established
without delay by the organizations concerned. The work in connection with
this installation will be accomplished by night or, if in daytime, by small palrties observing the greatest care to prevent enemy observation.
2. Special instructions for wireless liaison will be as published by the
Division.
3. The telephonic liaison will, whenever practicable, be doubled by optical
liaison, which will be established without delay.
4. After the advance of the elements of the Divisional Artillery has
begun telephonic and wireless communication will be established as soon as
practicable. Pending its installation, attention is called to the importance of
visual signalling, particularly semaphore, which it is believed has not been sufficiently employed in past operations.
V. INFANTRY BATTERIES
1. The following batteries are designated as infantry batteries to accompany the 84th and 83rd Infantry Brigades, respectively. The battery commanders concerned will report without delay to the respective brigade commanders
for instructions. These batteries will take position with their battalions and may
be used by their regimental commanders; but, after the capture of the first
enemy position, they will be ready to advance in close support of the infantry,
subject to the orders of the respective brigade commanders. The piece limbers
of these batteries and two filled caissons per gun will be advanced at the hour
H, or as soon thereafter as practicable, to the immediate vicinity of the battery
positions, and there held under cover.
Battery B, 151st Field Artillery.
Battery F, 149th Field Artillery.
2. The 3rd Trench Mortar Battery (5-inch Stokes motorized) is attached to the 84th Infantry Brigade as accompanying artillery and its commanding officer will report to the C.G., 84th Infantry Brigade for instructions.
3. The artillery commander in each subsector will detail one officer, two
non-commissioned officers and ten men, who will be instructed without delay in
the handling of enemy material, and will be provided with range tables for its
use. These detachments will go forward with the infantry of each brigade
for the purpose of turning captured artillery against the enemy.
VI. FUGITIVE TARGETS
1. One battery from each of the battalions listed below will be designated for fire on fugitive targets, and a call for such fire will, upon receipt by
the batteries in question, become a mission of first urgency. The wireless stations of these battalions will listen in constantly during daylight hours after the
hour H on D day.