THE MILL EIVER DKLTxV.. 637 



various c-ircumstances, poiuts to a comniou cause, and is, I think, connectt-'d 

 with the lowering of the upper portion of the valley, thus lessening- the 

 pitch to the southward. Brooks from the north and south now join and 

 break through the barrier near the south line of Hatfield, and have carried 

 out much of the sand, so that one can not decide whether the high sands 

 formerly filled it entirely. It is certain that the sands of West Brook 

 spread very slowly southward, and that the Avaters entering by the central 

 break in the ridge spread north and south, throwing down clays uj) to high 

 level, and that the high delta sands encroached i;pon them from the north as 

 the growth of the delta went on. 



THE MILL RIVER DELTA IN NORTHAMPTON. 



Farther south, on the north line of Northampton, the western rim of 

 the valley, which has come down southward, from the northwest corner of 

 Greenfield, swings southwestward and runs back of Florence, by the bridge 

 at Leeds, to Londville, where it turns at right angles and runs for two miles 

 southeast befure it regains its southward course. The bay thus formed was 

 studded with a great number of islands, all of till, for the rocky floor lies 

 everywhere deep below the surface. They are the drumlius already 

 described. Into this bay flowed the waters of four large streams, two of 

 which are dignified by the name of river, and they, together, filled tlie l:)ay 

 and sent great quantities of detritus out into the valley, to be carried south- 

 ward by the main stream. 



Their common delta has been greatly cut away by the streams them- 

 selves in their subsequent oscillations as they followed the margin of the 

 great river downward during the period of shi'inkage, and one must know 

 the comitry well and draw much on the imagination to reconstruct the broad 

 plain as it formerly spread across from Elizabeth Rock to Loudville and out 

 from Leeds to the border of the Meadows. Mill River has been espe- 

 cially destructive, and, as its mouth advanced from Leeds to its present 

 place, it has worn out all the broad basin in which it flows, and its tribu- 

 taries have cut out the peculiar depression of the " Bay State." One must 

 think of all this area raised- to the level of and merged into the Florence 

 plain in order to reconstruct this, by far the largest delta deposit of the high 

 bench upon the west side of the river. 



Along the road from Florence to West Farms, and then to LoudA-ille, 

 one rides for several miles over a sand plain (1 s h) about 305 feet above sea, 



