- 84 ' Notice of a Geological Model. 
gold medal, in 1830, was the first which had been exhibited in 
been exhibited in London; the one represents the field and battle 
& 
that excellent institution. A recommendation to adopt the more 
frequent application of the system, has been occasionally urged 
y prominent geological authorities. Since the date referred to 
two most elaborately executed models, on a very large scale, have 
of Waterloo, the other depicts the beautiful lake scenery of the 
north of England; both of them the result of vast labor and sin- 
gular perseverance. Those models which, in Germany and some 
other mineral countries, represent the itera economy of the 
mines and mining operations, belong to a class extremely useful, 
but different to that which has given rise to the present memoir. 
We come now to the consideration of the model before us. In 
point of mineral value, of geological peculiarities, of statistical 
intricacy, and of highly picturesque features, the district here ‘ 
represented in miniature, yet with sufficient faithfulness as re- 
gards characteristic distinctness, has perhaps no equal, within a 
similar area, in America. Itsa proximation to the tide waters of 
the Atlantic coast, moreover, ers upon it a commercial val- 
ue, in connection with the sources of industry and of remunera- 
tion for labor, manifestly within its limits. We are justified in 
adverting to these circumstances, because the useful results, and 
the beneficial application of science in economic geology, form 
legitimate objectae of associations like oa which I have the honor 
a seven hundred and 
rile sth forty five miles, and in 
width sixteen mails. It states in Tenia from four miles 
above Harrisburg, northward, to Millersburg on the Susquehanna, 
at the junction of the Wiconisco railroad. In length it reaches 
from the western extremity of the Cove mountain, on the west 
side of the Susquehanna to within eight miles of Pottsville. It 
comprises the two forks into which the Schuylkill coal-field sep- 
arates, opposite to Pinegrove, in the Swatara region. 'The north- 
ern fork or branch extends to the Wiconisco Coal Company’s 
mines at Bear Gap, and the southern branch stretches towards 
the Susquehanna in a southwest direction, to within about a mile 
of that river. The coal formation along several miles of the 
western portion of this lower fork, is reduced to a narrow ridge, 
_ which can scarcely be expected to contain coal to any valuable 
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