Sketch of W. ir. Mather. — Hitchcock. 3 
toric and Genealogical Society, and to a similar notice in 
Appleton's Popular Science Monthly for August, 1896. The 
accompanying portrait represents Prof. Mather as he appeared 
at the age of fifty-three, not long before his death, when in 
the maturity of his powers. The portrait in the Popular Sci- 
ence Monthly was taken in 1846, when forty years of age. 
The most important of Prof. Mather's writings may be the 
''Geology of the First District of New York,'' which afforded 
a larger list of formations than any of the other districts. It 
included — using the nomenclature of to-day — the Archean, 
Cambrian, Silurian, Devonian, Triassic, Cretaceous, Tertiary, 
and Quaternary. He must have been forward among his col- 
leagues in the establishment of the "New York System" and 
in the use of local names for the subordinate divisions. In 
his report for 1840 this system was said to consist of the 
Catskill, Helderberg, Shawangunk, and Hudson River. The 
first included the Chemung, the third was composed of rocks 
quite different from the Niagara, Clinton and Medina, of the 
Ontario division, and the Hudson series embraced all the 
Lower Silurian, including the Potsdam. Two of the geolo- 
gists — Hall and Emmons — excluded the Catskill from their 
enumeration, calling it simpl3^"01d Red Sandstone." The 
order of description was from above downwards in obedience 
to tiie general usage of tiie time. 
Mather had been commissioned by the American Associa- 
tion of Geologists in 1840 to present before them the subject 
of the "Drift." Not being in readiness to present his paper 
in 1841, and being absent from the next two meetings, he used 
the material, chiefly gathered in his own state, for his official 
report. This is unusually full and is one of the best presen- 
tations of thesubject in his time. The Quaternary is divided 
into three parts, Alluvium, Quaternarj'^ proper, and Drift. The 
description of the first relates to fluviatile, lacustrine, and 
marine alluviums, low-lying sands, bars, mud flats, peat, marl, 
bog iron, tufa, beaches, shoals, spits, dunes, together with full 
descriptions of all the fossils contained in these deposits, es- 
pecially the Infusoria [Diatoms], This topic also embraced 
springs, caves, transportation by floating ice, the disintegra- 
tion of rocks, and denudation. 
The second division related to the modified drift — river 
terraces, beaches bordering the great lakes, sand and gravel 
