ty of jobs—as a carpenter, insurance salesman, keeper of atemperance el—before taking a position as a janitor at Anderson’s (noy ofStrato do muco pass many quiet evenings in ty library teacronomy, atics, and to produce a string of papers, icular empions ofEart on climate.

    Croll  to suggest t cyclical c, fromelliptical (o elliptical again, mig and retreat of ice ages. No one  before to consider an astronomicalexplanation for variations in Eart entirely to Croll’s persuasivetain began to become more responsive to tion t at some formertime parts of ty and aptitude  tland and widely honored:

    y in London and of ty of St. Andrews, among much else.

    Unfortunately, just as Agassiz’s t last beginning to find converts in Europe, aking it into ever more exotic territory in America. o find evidence forglaciers practically everyually  ice inguised. None of ted supported suced country ature greil ly beloy.  it necessary to appoint to take hisplace.

    Yet, as sometimes ly out of faser e t ts may noed ation.”

    Part of t Croll’s computations suggested t t recent ice ageoccurred eigedt Eart of dramatic perturbation mucly t.

    it a plausible explanation for  migime except t in tin Milankovitcial motionsat all—raining—developed an unexpected interest in tter. Milankovitc t t it  but t it oo simple.

    As Eart is subject not just to variations in ts orbit, but also to rs in its angle of orientation to ts tilt and pitcing tensity of sunligcicular it is subje