N.J. Stat. § 51:3-1
The board of chosen freeholders of each county shall erect, and properly inclose and protect at public spots, adjacent to the courthouse of the county, two substantial pillars on the same meridian line and not less than one hundred feet apart. The board shall cause to be determined the accurate latitude and longitude of the first of said pillars, reckoning the longitude from the meridian at Washington, and shall have said latitude and longitude distinctly and legibly marked on said pillar in degrees, minutes, seconds and parts of a second. Upon the summit of the first pillar there shall be immovably placed a brass plate, indented with a line indicating the true meridian. There shall also be placed on said first pillar a hair sight, in such a manner that a straight line passing through the center thereof, extended to a distinctly visible needle point, which shall be maintained on the summit of the second pillar, will be in the line of the true meridian running north and south. The board shall cause the said meridian line to be verified at any time, when required by order of any judge of the Superior Court.
N.J.S. § 51:3-1