78 The American Geologist. August, 1897 
pai-ativel}^ modern times, happened to dwell upon the siii-face; 
nor can it fail to strike one as absurd, that the rocks forming 
a large portion of this continent and that of northern Europe 
should be called after the former inhabitants of a small tract 
of country in England and Wales. We object," he adds, "to 
the introduction of mere local names into general geology, 
and would prefer a numerical arrangement, when it can be 
generally agreed upon by the scientific men of Europe and 
America. It will be better to adhere to the old groups, pri- 
mary, transition, secondary and tertiary, since these are uni- 
versally understood and convey with sufficient accuracy the 
ideas of their arrangement, while each group may be subdi- 
vided at pleasure, into as many strata as contain peculiar fos- 
sils." 
With this commendable project, not however without a lean- 
ing towards the Wernerian mineralogical school, Jackson was 
throughout consistent. 
In not one of the three New England states on which he by 
priorit}'^ of his surveys had the privilege of placing rock names 
of his own choosing did he leave a local designation or fasten 
a system of stratigraphy differing from that previously known. 
His reason for not applying rock names seems to have depend- 
ed more upon his ideal of a geok)gical nomenclature than up- 
on doubts in regard to the identity of important groups. It 
is somewhat remarkable to note him working in this manner, 
refraining at every step from a practice, which his contempo- 
raries west and south of the Hudson were following, mainly 
with success in New York state. But the conditions differed 
vastly on the opposite sides of this river. There was little 
incentive in Jackson's environment to make out a time scale 
for the rocks. The gnarled and topsy-turvy stratigraphy of 
eastern Massachusetts may afford a birth-place for a James 
Hall, but it will not rear him. He must be transplanted while 
young and impressionable to a region of more orderly rocks 
than that of Hingham. Jackson's mind responded to a ter- 
rane in which chemical, mineralogical, and structural questions 
predominate over the clearer facts of vertical succession, as 
presented west of the Taconic range. 
In view of the complexity of New England geology and of 
the time at his disposal for the elucidation of the intricate 
