In the discharge of their duties the commissioners shall have the power and authority to:
a. Examine witnesses under oath to be administered by any one of the commissioners;
b. Employ certified court reporters or other means for the purpose of recording the testimony of witnesses;
c. Employ surveyors to run, survey, ascertain and mark the boundary line; and
d. Cause maps on a scale of not less than 2 inches to the mile and surveys to be made of the boundary line as fixed by them.