Thomas Burnet's Battleground of Time - Time's Arrow, Time's Cycle: Myth and Metaphor in the Discovery of Geological Time - page 54

arise again within the new pile of sediments (figure 21), and the crust of
flood deposits finally collapses into the interior spaces, leaving the earth as
we find it today (figure 20).
Steno's allegiance to time's arrow pervades more than his figures. He
explores and defends this general approach to history at length—and with the
same arguments that Burnet used. Steno agrees with Burnet that a
reconstruction of the earth's past must rest upon signs of history preserved in
the current form of objects. We must learn (262) "in what way the present
condition of any thing discloses the past condition of the same
thing" ( quomodo praesans alicuius rei status statum praeteritum eiusdem rei
detegit ). As his chief criterion, Burnet proposed the disorder of the earth's
surface as a sure sign of change from original perfection. Steno uses the same
argument. His original earth is a smooth pile of sediments, and their
disruption provides his explicit criterion of history: "inequalities of surface
observed in its appearance today contain within themselves plain tokens of
different changes" (262).
Had I relied upon the available published figure, I might never have grasped
the richness of Steno's conception or discovered its similarities with Burnet's.
But one day, for aesthetic pleasure and as a sort of sacrament, I turned
through all pages of an original copy of the Prodromus . When I came to
Steno's own version of Tuscan history (Figure 2.10), I immediately noted the
difference from later reproductions, but I did not at first appreciate the
significance of this alteration.
Steno did not group the six stages in one vertical column, but in two sets of
three, one beside the other. Later historians have rearranged the figure
according to modern conventions, with geological time flowing in one
direction as a set of strata, oldest at the bottom. I can only suppose that they
accorded no special significance to Steno's choice—for none have
commented upon the reorientation. Perhaps they assumed that Steno placed
his figures so oddly (by modern convention) because he had to fit all six on
the lower part of one sheet, below several figures of crystals—and had no
room for a single vertical column. Perhaps, since pictures usually receive