Sentence:  Whenever any boats or floats moving in opposite directions, approach a place in the Canal which is less than thirty feet wide on its surface, or which will not safely permit their passing, it shall be the duty of the master of the boat or float ascending the Canal, to stop at such distance from such narrow place as may be convenient for the descending boat or float to pass through such narrow place, and there wait until such passage is effected: Provided, however that a descending boat or float, that is not a licensed <WSD>packet boat</WSD> which is about thus to meet an ascending licensed <WSD>packet boat</WSD>, shall stop and give place for the said licensed <WSD>packet boat</WSD>, first to pass through the said narrow place;- and, provided, also, that descending rafts shall, in all such cases, stop and give place for boats and every other description of ascending floats first to pass through the same. 
Meaning of the word marked with <WSD> tags:  A boat that carried mail, cargo, and, in later years, some passengers along a regularly scheduled route up and down a river or canal.