Dodge.] 
198 
[May 18 , 
The base assumed for city purposes is 0.64 feet below mean 
low water, and to this level points at the surface whence depths 
are measured will be referred. 
At the Boston Gas Company’s works, near Copp’s Hill, at a 
point about 24 fe'et above the chosen base line, an artesian well 
was sunk some 80 feet before slate was reached, and then pene- 
trated rock to a depth of about 1700 feet. 
Crossing the tract which was formerly the mill pond, we come 
upon natural land again at Barton’s Point. Here is an outlying 
spur of Beacon Hill, north of Cambridge Street, an independent 
elevation in fact, although too small to be enumerated in the same 
category with Beacon, Fort and Copp’s Hills. The saddle con- 
necting it with Beacon Hill lies, roughly speaking, between Blos- 
som and South Margin Streets, with its ridge descending by 
Temple and Stamford Streets to the corner of Lynde and Green 
Streets, rising again on Chambers Street to a highest point, 35 or 
40 feet above low water, near the upper end of Poplar Street. 
The original area of the neck of land upon which this hill stands 
extended only about to Lowell and Brighton Streets. Their angle 
was Barton’s Point. Of the two streets laid down here on the 
1722 map, one followed the course of Leverett Street to Barton’s 
Point, and the other was substantially Poplar Street. As is well 
known, the city limits have been largely extended here as else- 
where, by additions along its water front or by filling bays. 
Along where formerly the line of the shore ran, the ground surface 
is at present 15 or 16 feet above our assumed base line, and un- 
broken by any outcrop, but the rock rises nearly to, and at points 
above, low water level. From the sea-wall, between the angle at 
the foot of Pojfiar Street and Leverett Street, a shoal makes out 
into the river, bare at low tide. 
Soundings made by the Improved Sewerage Company along 
and in the vicinity of North Charles Street, from between Allen 
and Poplar Streets around the foot of the hill to the corner of 
Brighton and Lowell Streets, reached the ledge at depths vary- 
ing from 13 to 28 feet. 
Further south aloog Charles Street, in the district where was 
formerly a bay, the borings did not reach rock. 
These soundings confirm each other, so that the liability to oc- 
