Labor was not easily procured, probably from the scarcity of laborers, as the wages paid, $10 a month and board, were presumably as much as could be earned in manual labor elsewhere. "An order was sent to England for a levelling instrument made by S. & W. Jones, of London, and this was the only instrument used for engineering purposes after the first survey by Weston." Two routes were considered; the rejected route was forty years later selected for the Lowell Railroad. The canal, 30 ft. wide, 4 ft. deep, with 20 locks, 7 aqueducts, and crossed by 50 bridges, was, in 1802, sufficiently completed for the admission of water, and the following year was opened to public navigation from the Merrimac to the Charles. Its cost, about $500,000, of which one-third was for land damages, was but little more than the estimate. Commencing at Charlestown mill-pond, it passed through Medford, crossing the Mystic by a wooden aqueduct of 100 ft., to Horn pond in Woburn. Traversing Woburn and Wilmington it crossed the Shawshine by an aqueduct of 137 ft., and struck the Concord, from which it receives its water, at Billerica Mills. Entering the Concord by a stone guard-lock, it crossed, with a floating tow-path, and passed out on the northern side through another stone guard-lock; thence it descended 27 ft., in a course of 5-1/4 miles, through Chelmsford to the Merrimac, making its entire length 27-1/4 m. The proprietors made Charlestown bridge the eastern terminus for their boats, but ultimately communication was opened with the markets and wharves upon the harbor, through Mill Creek, over a section of which Blackstone street now extends. As the enterprise had the confidence of the business community, money for prosecuting the work had been procured with comparative ease. The stock was divided into 800 shares, and among the original stockholders appear the names of Ebenezer and Dudley Hall, Oliver Wendall, John Adams of Quincy, Peter C. Brooks of Medford, and Andrew Craigie of Cambridge. The stock had steadily advanced from $25 a share in the autumn of 1794 to $473 in 1803, the year the canal was opened, touching $500 in 1804. Then a decline set in, a few dollars at a time, till 1816, when its market value was $300 with few takers, although the canal was in successful operation, and, in 1814, the obstructions in the Merrimac had been surmounted, so that canal boats, locking into the river at Chelmsford, had been poled up stream as far as Concord.