LOBECK, NEW YORE CITY, A PHYSIOGRAPHIC CENTER 33 



Washington, either by boat or train via Eichmond. The drowned 

 Chesapeake Bay is to be seen if the first alternative is adopted, and 

 some of the folios of this region should have been glanced over. The in- 

 vestigations of Darton, Shaler, Willis, Fontaine, Clark, Miller, Hunter, 

 and especially McGee (184, 185), throw light upon this region. In 

 case the Eichmond route is taken opportunity is given to see some of the 

 isolated Triassic occurrences of the south and to note the location of the 

 Fall Line. Darton' s Eichmond bulletin (172) may be useful as well as 

 Surface's (160) account of the physiography of Virginia. At Washing- 

 ton a visit should be made by electric car to the Great Falls of the 

 Potomac, and realization should be had of the high and low terraces of 

 the Potomac Eiver. The necessary data may be foimd in the Washing- 

 ton Folio. From Washington a splendid electric line runs sixty miles 

 over the rolling Piedmont country to Bluemont at Snicker's Gap on the 

 Blue Eidge (Fig. 26). During this ride other occurrences of the Triassic 

 are to be seen. From this point the traveler should walk over the ridge 

 into Shenandoah Valley to take the train for Luray. The important 

 literature covering western Virginia physiography and related topics is 

 in the form of a report by Keith (154) on the Catoctin belt, Bascom 

 (150) on the Piedmont, Geiger and Keith (153, 163) on Harpers Ferry, 

 and Surface's (160) article already mentioned. An account of the Luray 

 Caverns appears in the National Geographic Magazine (127). The next 

 lap of the journey is by train to Cumberland, Maryland. The entrenched 

 meanders of the Potomac Eiver below the even crest of the folded Appa- 

 lachians are followed by the railroad. The structural relations of the 

 various ridges may be learned from the Papaw-Hancock Folio of the U. S. 

 Geological Survey. Additional valuable material may be found in Clark 

 and Mathew's Maryland Survey report on the physical features of the 

 State (265), and articles by Clark, Martin, and Campbell. Between Cum- 

 berland and Altoona the traveler rides in the broad longitudinal valley at 

 the foot of the Allegheny Front (Fig. 22). After a visit to the crest of 

 the plateau he may continue east to Philadelphia, stopping at Harris- 

 burg on the way. Topics and literature pertaining to this important 

 section have been mentioned. A day around Philadelphia gives occasion 

 to see the falls of the Schuylkill, now artificially modified, and the ter- 

 races marking a former shoreline on the oldland in Fairmont Park. A 

 trip out to Chester Valley is well worth while. The main elements of 

 Philadelphia physiography are outlined in the Philadelphia Folio. If 

 the traveler does not now feel obliged to come on to New York he may 

 take train for Wilkes-Barre and Scranton and on the way enjoy a ride 

 on the very crest of some of the Appalachian ridges in the Pottsville coal 



