the highest point of the canal and is the present location of the Middlesex Canal Association's museum. Freight boats required 18 hours from Boston up to Lowell, and 12 hours down, thus averaging 2.5 miles per hour; passenger boats were faster, at 12 and 8 hours, respectively (4 miles per hour). As seen on later American canals, use was not restricted to freight and transit: people from the city would ride passenger boats on daylong tourism excursions to the countryside and take vacations in luxuriously fitted out canal boats, whole families spending a week or two lazing along the waterways in the heat of summer. Freight statistics compiled for twenty years cited in the Harvard Economic study by Roberts indicate the downriver trips from Concord to Boston took four days, and the reverse trip upriver took on average five days. A round trip between Boston and Concord, New Hampshire usually took 7–10 days. These speed limits were set and maintained by the board of proprietors to prevent wakes from damaging the canal sides. Roberts noted they were unlikely to be enforced, and generation of a shore damaging wake would require sails or animals to drive a canal boat in excess of , which would require dangerously stiff breezes in the correct direction. The canal was one of the main thoroughfares in eastern New England until a few decades after the advent of the railroad. The Boston and Lowell Railroad (now a part of the MBTA Commuter Rail system) was built using the plans from the original surveys for the canal. Portions of the line follow the canal route closely, and the canal was used to transport construction materials and also an engine for the railroad. The canal was no longer economically viable after the introduction of railroad competition, and the company collected its last tolls in 1851. The Middlesex Turnpike, incorporated in 1805, also contributed to its downfall. Investors who held their shares in the company lost money: shareholders invested a total of $740 per share but only reaped $559.50 in dividends. Those who sold their shares at an appropriate time made money: shares valued at $25 in 1794 reached a value of $500 in 1804 and were worth $300 in 1816. Before the corporation was dissolved, the proprietors proposed to convert the canal into an aqueduct to bring drinking water to Boston, but this effort was unsuccessful. After the