ST. JOHN: SABLE ISLAND. 23 
The sea was now witliin 12 feet of the West Lighthouse, a splendid 
tower built in 1873 at a cost of $40,000. During two days of un- 
usually quiet weather, a heavy ground-swell set in from the south- 
east undermining the embankment till the lighthouse canted over 
dangerously. Before the crash the apparatus was removed. Later it 
was installed about a mile further east. The sea continued to ad- 
vance and in 1888 the light was again removed, two miles farther east. 
From this time, another period of comparative stability started. 
It will be seen that such has been the regular course of events: dur- 
ing a few years every storm causes violent destruction of a part of the 
island, then follows a period of 10, 20, or 40 years of quiet. This is 
probably to be explained by the protecting action of the sand washed 
from the island and deposited on the surrounding bars during the 
years of active erosion. The building-up of these bars makes a pro- 
tecting ring upon which the Avaves break their fury before reaching 
the island. When these l)ars have been worn down the waves can 
again vigorously attack the island, and another period of destruction 
ensues. 
We have no more recent survey, but only the observations of those 
stationed on the island, which tell us that it is now twenty miles long, 
less than one mile broad, and its highest point, Rigging Hill, nearly 
100 feet high. 
Changes ix Wallace Lake. 
The physical changes in Sable Island are also e\idenced in Wallace 
Lake, the great salt-water pond that occupies the center of the island 
for over half its length. 
Le Mercier gives us our first good account' of this lake, in the year 
1753. "Within these seven or eight Years, Providence hath opened 
a Communication between the great Pond (fifteen ]\Iiles long) and 
the Sea, which hath made a safe and large Harbour; but tlie Entrance 
is barred so that large and sharp Vessels cannot get into it; but as 
there is about 8 Feet of Water over the Bar at higli Water there is 
sufficient Passage (as we know by Experienced for Vessels of 30 Tuns 
or more, if not built Sharp." 
On Des Barres' cliart from the survey of 17G() and 1707 the lake is 
shown very much as at present, but witli a broad opening to the sea 
through the dunes on the north side, with soundings in its center of 
1 Boston Weekly News Letter, February 8 (17o3). 
