The Sight Glass

The vented air settled, leaving the subfloor trench completely still. Two paces past the sediment trap, the conduit terminated at a cast-iron junction housing bolted into the foundation wall. A round brass sight glass sat flush against the faceplate, obscured by a film of white mineral dust. I wiped the glass clear with my sleeve. Beneath the pane, three stamped brass indicator dials rested inside the housing, frozen at zero. I slid the tip of my straightened wire probe through the casing's relief notch, nudging the primary gear wheel. The brass ratchet gave one crisp, metallic click. The first digit turned cleanly to one. The recorded mechanism is intact.