Lowell continued to be in the forefront of new industrial technology. In 1828, Paul Moody developed an early belt-driven power transfer system to supersede the unreliable gearwork that was utilized at the time. In 1830, Patrick Tracy Jackson commissioned work on the Boston and Lowell Railroad, one of the Oldest railroads in North America. It opened five years became independent in 1845, patent medicine factories like Hood's Sarsaparilla Laboratory later, making the Middlesex Canal obsolete. Soon, lines up the Merrimack to Nashua, downriver to Lawrence, and inland to Groton Junction, today known as Ayer (renamed after Lowell patent medicine tycoon Dr. James Cook Ayer), were constructed.