Geologn in the High ScJiool. — Alder son. 285 
glaciated i^epples, bowlder clay and glacial stria' on the 
Niagara bed-rock. These facts, together with the observations 
on the many bowlders scattered over this region leads them 
on instinctively to the glacial theory as an explanation. The 
Niagara outcrops at south Chicago, eleven miles south of the 
city, at Bridgeport within the old city limits, at Hawthorne 
five miles west on the Chicago, Burlington & Quincy R.R., at 
Thornton twenty miles south on the Chicago & Eastern Illi- 
nois R.R., and at Joliet, all of which places they visit, collect 
materials for their work and gather the nucleus of many pri- 
vate cabinets. From the bowlders they gather an almost end- 
less supply of specimens for the study of mineralogy and lith- 
ology. At south Chicago they gather Favosites niagarensis, 
Cargocrinus orfiatus, Orthoceras scatmnoni, Ortlioceras 
annulatiivi and beautiful samples of pyrites. At Bridgeport, 
the most fruitful field, they get Eucalyptocrinus chicagoensis, 
E. ornatus, E. cornutus var. excavatus, Icthyocrimis corhis, 
Amphiccelia neglecta^ Strophomena rhoinboidalis, Glypto- 
crinus ornatus, and many other species. At Thornton they 
find Stromatopora concentrica, excellent specimens of geodes, 
and bitumen in abundance. At Joliet they find many speci- 
mens of Calymene niagerensis. They frequently find rare 
specimens, as Calymene niagarensis at Stone}'^ island — the 
first I have known to be found there. In fact hardly an excur- 
sion is made that does not develop some new fact about our 
home geology and their appetite becomes whetted for more 
discoveries. But the commoner forms, such as I have men- 
tioned, are the only ones that are made the basis of class 
room work and all are expected to find at least one specimen 
of each. 
Before each trip is made a list of questions and suggestions 
is given the class in order to enable them to observe the geo- 
logical features to be met. After the return as much time is 
taken as is needed for a retrospective view, discussion, and 
explanation of what has been seen. For example : one excur- 
sion is to a part of the ridge, or terrace known as Forest Hills. 
Where the road cuts into the terrace, stratified sand is found 
at the very top. The United States Geodetic Survey gives 
the altitude of Morgan park — which is at about the same level 
— at 84 feet above lake Michigan. Discussion then brings to 
light the facts relative to the former high level of the lake, the 
