1 8 The Taconic — Marco^i. 
iS6o, a change was made under the pressure of that joint paper 
of Barrande and Marcou. At first the geological survey of 
Canada maintained its stratigraphic position unassailable, but 
after weighing carefully the contents of the paper, and the 
consequences which might follow, the Director, Logan, without 
going over the field at Georgia or at Points Levis and Mont- 
morency — a material impossibility for the ground was buried 
under four feet of snow since the first day of December and even 
before — wrote his printed letter to Barrande, dated 31 Dec. 
i860, in which he admits "an overturn anticlinal fold with a 
crack and a great dislocation running along the smmmit." Ac- 
cording to Logan that great fault, which he had failed to 
recognize in the field and in situ, during his eighteen years of 
explorations, finding it only in his ofiice at Montreal, on New 
year's eve of 1861, as an expedient and an explanation to change 
his base of the stratigraphic scale of Canadian geology — 
"passes the boundary of Canada not over a couple of miles from 
lake Champlain" east of Phillipsburgh; then "it proceeds in 
a gently curving line to Quebec, keeping just north of the for- 
tress; then it coasts to the north side of the island of Orleans;" 
"afterwards it keeps under the waters of the St. Lawrence to 
within eighty miles of the extremity of Gasp6, then again it 
leaves a strip of the Hudson River or Utica formation on the 
coast." "Remarks on the fauna of the Quebec group etc.," p. 
4, Montreal, 3rd Jan., 1861." Such a find made in an office of 
a geologist is unique, and shows a curious result of the joint 
publication of Barrande and Marcou. Not satisfied with one 
great fault, Logan in May 1S61, added a second great fault at 
Montmorencv opposite his overlapping fault of the Island of 
Orleans, and strange to say his successor Mr. Selwyn added to 
the two faults of Logan, a third great fault on the southern 
side of the island of Orleans, and has the courage to trace "the 
approximate course of the great St. Lawrence and Champlain 
fault" unhappily almost all the time buried under water, and 
stopped short just in the middle of the gulf of St. Lawrence. 
\Ma^ of the Dominion of Canada, geologically colored, 1S42 to 
1882.] 
However Mr. Lapworth disagrees with both Logan and 
Selwyn, in regard to the existence of those great faults for the 
