INTRODUCTION. XXIII 
obliterated by erosion from floating logs and driftwood during 
seasons of high water, while those upon the upper portions 
are being ruined by the visitors who cut names and dates over 
and upon the sculptured surfaces. Another place visited was 
on the Susquehanna River, 3 miles below Columbia, Pennsy]- 
vania. Here a small stream empties into the river from the 
east, along whose course several rocks were found bearing 
deeply cut and polished grooves, indicating a nearly east and 
west direction. These rocks are believed to be on the line of 
one of the Indian trails leading to the Delaware River, similar 
to that at Conowingo, Maryland, which was the last locality 
inspected, and which is known as “‘ Bald Friar.” A large mass of 
rock projecting from the bed of the river is almost covered with 
numerous circles, cup-shaped depressions, human forms, and 
ellipses, strongly resembling characters from other points in 
the regions formerly occupied by the Algonquian family. 
Measurements and sketches of these petroglyphs were made, 
with a view to future reproduction upon models. 
OFFICE WORK. 
The Director, Maj. J. W. Powett, has continued the work 
of the linguistic classification of the Indian tribes in North 
America north of Mexico, and in connection with it is prepar- 
ing a map upon a linguistic basis showing the original habitat 
of the tribes. The work is now far advanced. 
Prof. Cyrus THomas, as previously stated, has devoted much 
of his time during the year to the study of the collections made, 
and in preparing for publication the account of field work 
performed by himself and assistants. That account will form 
the first volume of his final report, and will consist almost 
wholly of descriptions, plans, and figures of the ancient works 
examined, narrative and speculation being entirely excluded. 
It will also include a paper by Mr. Gerard Fowke on the stone 
articles of the collection. The second volume will be devoted 
to the geographic distribution of the various types of mounds, 
archeologic maps and charts, and a general discussion of the 
various forms and types of ancient works. The preliminary 
lists of the various monuments known, and of the localities 
