▁( Nov ember ▁ 1 6 , ▁ 1 8 5 3 ▁– ▁July ▁ 2 1 , ▁ 1 8 8 8 ) ▁was ▁an ▁American ▁ge ologist ▁and ▁min eral og ist . ▁ ▁Career ▁▁ ▁Lewis ▁was ▁born ▁in ▁Philadelphia ▁and ▁educated ▁at ▁the ▁University ▁of ▁Pennsylvania . ▁He ▁received ▁his ▁Masters ▁of ▁Arts ▁D eg ree ▁in ▁ 1 8 7 6 ▁and ▁became ▁attached ▁to ▁the ▁Ge ological ▁Survey ▁of ▁Pennsylvania ▁in ▁ 1 8 7 9 . ▁He ▁served ▁for ▁three ▁years ▁as ▁a ▁volunte er ▁member , ▁and ▁during ▁this ▁term ▁he ▁became ▁greatly ▁interested ▁in ▁the ▁study ▁of ▁gla cial ▁phen omena . ▁In ▁ 1 8 8 0 ▁he ▁was ▁chosen ▁professor ▁of ▁min eral ogy ▁in ▁the ▁Philadelphia ▁Academy ▁of ▁Natural ▁Sciences , ▁and ▁in ▁ 1 8 8 3 ▁he ▁was ▁appointed ▁to ▁the ▁chair ▁of ▁ge ology ▁in ▁Ha ver ford ▁College , ▁Pennsylvania . ▁ ▁During ▁the ▁winter s ▁of ▁ 1 8 8 5 ▁to ▁ 1 8 8 7 ▁he ▁studied ▁pet ro log y ▁under ▁H F ▁Rosen bus ch ▁at ▁Heidel berg , ▁and ▁during ▁the ▁sum mers ▁he ▁investig ated ▁the ▁gla cial ▁ge ology ▁of ▁northern ▁Europe ▁and ▁the ▁British ▁Is les . ▁His ▁observations ▁in ▁North ▁America , ▁where ▁he ▁had ▁studied ▁under ▁Professor ▁G . F . ▁Wright , ▁Professor ▁T . C . ▁Chamber lin ▁and ▁Warren ▁U ph am , ▁had ▁demonstrated ▁the ▁former ▁extension ▁of ▁land - ice ,