face of the caisson, crawling slowly towards the pediment of
the nearest truss. Catalysis
Or cancer, as Helmuth could not help but think of it. On
this bitter, violent monster of a planet, even the tiny specks of
calcium carbide were deadly. At these wind velocities, such
specks imbedded themselves in everything; and at fifteen
million pounds per square inch, pressure ice catalyzed by so-
dium took up ammonia and carbon dioxide, building pro-
tein-like compounds in a rapid, deadly chain of decay:
H~NCHCO-HNCHCO-HNCHCO-HN….
Ca0 Ca Ca
I I
HNCHCO-HNCHCO-HNCHCO-HN… .
I I I
Ca0 Ca Ca
I I
HNCHCO-HNCHCO-HN… .
For a second, Helmuth watched it grow. It was, after all,
one of the incredible possibilities the Bridge had been built to
study. On Earth, such a compound, had it occurred at all,
might have grown porous, bony, and quite strong. Here, un-
der nearly eight times the gravity, the molecules were forced
to assemble in strict aliphatic order, but in cross section their
arrangement was hexagonal, as if the stuff would become an
aromatic compound if it only could. Even here it was mod-
erately strong in cross sectionbut along the long axis it
smeared like graphite, the calcium atoms readily surrender-
ing their valence hold on one carbon atom to grab hope-
fully for the next one in line
No stuff to hold up the piers of humanity’s greatest en-
gineering project. Perhaps it was suitable for the ribs of some
Jovian jellyfish, but in a Bridge-caisson, it was cancer.
There was a scraper mechanism working on the edge of