Relate the author's observation on the use of mar boats as a mode of river transport in Assam.
At the time of Rowntree's stay in Assam, transportation could be made only through the rails and the ships or boats. More usually, crossing the rivers was made in a mar boat, a tedious performance at the best of times. The mar, which was a ferry, consisted of a plank platform covering two open boats placed alongside one another. These were either paddled across the river, connected by a running cable to another stretched across the river, were propelled from one side to the other by the force of the current. This ingenious device worked very well, but constant adjustments had to be made to allow for the rise and fall of the rivers. A whole series of ghats, or landing places, had to be constructed at different levels on the river bank.