For me, by some distance
A mass of mummified, necrotic flesh, a placid, proboscidian horror on an insane scale fused with, penetrated by, united with and grown out of the great machine, a great ithyphallic stiff with ribbed tubes and seemingly severed or dissected at the glans yielding a vaginal outline pierced by thirteen urethrae.
One cannot tell where machine ends and flesh begins, machine-flesh and flesh-machine all seem to have sprouted and grown, the derelict, the machine-chair and its jockey (an interesting word) all one, all belonging to a nightmare vision, inconceivable apart, entirely penetrated by the wires and tubes of his function and a physical part of the biomachenery. I cannot imagine nor would wish to imagine how such a thing came into being: it is presented to us as a consummated union, biology and machinery inseparable, more than merely fused. ''And they shall become one flesh''.
These thoughts are barely adequate to express my own deep fascination with and disturbance by erotomechanica.