The Cistern Whale

What it looks like, and what it does

A vast dark flank curving along a vaulted brick cistern, the arches reflected in a lantern-lit surface. An eye the size of a manhole cover rolling slowly toward a service ladder. Tiny figures with torches on a catwalk.

Surfaces rarely. Sings in autumn. Answers a particular note struck on the drain grating.

What is known

The Aldgate cistern was built in 1869 to hold twelve million litres. Inspections have measured the animal at nearly twice that volume. Inspection crews disagree about its colour.

Its song is audible in the pipes, in kettles, in bath water. On the nights it sings the city's tap water tastes of tin and distance, and residents dream of deep water. It has been seen to rise when the city is in mourning.

What it can do

• Occupies a volume beyond the measured capacity of its cistern
• Sends its song through the water supply to every tap in the city

Where it stops

• Cannot be heard through bottled water
• Has not been disturbed since 1971, when the cistern was last drained and the song stopped for eleven weeks

An encounter

Kowalczyk lowered a lamp on a rope and saw a surface that moved like breathing. She struck the grating with a spanner, once. After a minute the surface sounded back a single note, which she later matched to the kettle in her kitchen. She filed the inspection as satisfactory.

Wanda Kowalczyk, municipal water engineer, Aldgate cistern, north chamber, Annual inspection, October

What is established, and what is only said

• established: Hydrophones in the cistern record sustained tones in the 17 to 30 Hz band during autumn.
• rumor: That the council paid for a new roof in 1952 to keep the sound in.
• interpretation: It may not have entered the cistern. The cistern may have been built around it.

Still unresolved

The cistern has no inlet large enough for the animal to have entered. The brickwork over the stairs was laid in 1869 and has never been breached.

Where it has been recorded

• The Aldgate Cistern (confirmed) — Recorded by Wanda Kowalczyk, municipal water engineer.

Stories about it

• The Song in the Aldgate Cistern (Grotesque encounter, 4 min) — A water-board inspector climbs down into the old Aldgate cistern to close a valve and meets the whale that lives in the reservoir, and the song it sings in the pipes is the same one his mother hummed.

Connected entities

• The Lullaby Engine — Both sing to a city through its infrastructure, and neither has been asked to stop.
• The Anchorite — Both are large, patient presences in water that serve a community by being heard, and neither has been seen to ask for anything.
• Choir Reef — Both are enormous things heard through water that no one commissioned. People come to listen. Neither stops.