The local machine
22 plates
Generated plates for the brass, the chart and the deck, with 6 ambience beds, and one geographic file for the Scilly coastline.
Real-time film · 5:44 · production notes · 16 to 17 October 2026
15°
A wordless, code-drawn film of five minutes forty-four seconds on the longitude problem, from an astrolabe’s stereographic projection and a week of dead reckoning to Harrison’s grasshopper escapement and the five-beat-a-second H4, with a narrated edition made an hour later. It was built in a Cursor chat by Claude Sonnet 5.5. This is what the log shows.
The session in four numbers
From a request to two published films
1 h 36 minfrom the request at 20:47 to the narrated MP4 at 22:24, plus a two-minute publish next morning
279tool calls recorded, from 22:21 onward
3,257lines added across 22 files
no costCursor logged no token usage for this chat
5:44 film1920×1080 at 306 chapters13 shots0 narrated words in the original, 690 in the narrated edition22 plates6 ambience beds2,226 lines of film code
The evening
20:45 to 22:30
The first row is the tool calls Cursor kept; the second is every moment the agent wrote code, which covers the whole evening; the third is your messages. The local rows mark each plate and ambience bed. The next-morning publish at 05:29 is outside this window.
Cursor agent, claude-sonnet-5-5Code and messagesLocal machine, no API cost
The log
What Cursor kept
What the agent did
Counted from the tool-call records in Cursor’s own store. These are the calls from 22:21 onward, so they undercount the opening 90 minutes.
What Cursor recorded
Cursor keeps the context size but writes zero for input and output tokens, so no dollar figure can be derived. The page shows what was measured and leaves the bill out.
The film
What the evening produced
The score
D minor to D major
A chamber horology score at a 60 BPM clock pulse that subdivides to 300 BPM in Act IV. D major arrives only at the Deptford trial. The mix peaks at −1.7 dB with no clipping.
The narrated edition
33 lines, 690 words
Read by am_fenrir with the 10 dB music dip, built beside the original without touching it. Six sync points were checked against the picture.
The MP4s
10,320 frames, 1.03 GB
1920 by 1080 at 30 fps, matching the live page to about 0.6 of 255 levels. The narrated MP4 reuses the original video with the audio swapped, and has its own showcase card.
What review found
Eight findings across the hopper passes and the narration
The review log names each defect with the frames that showed it, and the final reports list what was left.
| Found | What went wrong | How it was handled |
|---|---|---|
| Hopper draft: staging | The mechanism filled 40% of the frame, dead centre in a brown void, with brass on brown and no frame or context | Rebuilt in world units with a camera, brass pillars and bridge framing it, and a blued-steel bed so the brass separates |
| Hopper draft: the levers | Thin sticks like tweezers, with pallet pads floating off the teeth and the pendulum bob colliding with the wheel | Redrawn with pivot bosses, counterweight lugs, steel pallet pads and fingers, and a longer pendulum so the bob clears |
| Pass 1 recheck | The pin was mirrored relative to the rod, and hub and lug circles unioned into the lever path drew stray ring outlines | Rotation sign fixed; bosses made separate raised parts |
| Pass 2: material and meaning | The steel bed read as a flat gradient, nothing tied the wheel to time, and the wheel step looked like a teleport | An engraved 60-mark seconds ring, a carmine index fixed to the wheel angle, a three-copy shutter trail on each step and higher bar texture scale |
| Scilly wreck | The film could have blamed the 1707 loss on a longitude error | The sources put it on latitude and chart errors, so longitude enters only as the reason for the 1714 Act |
| Narration names | Respellings such as Silly for Scilly, Eye-oh for Io, rum line for rhumb line and ree-tee for rete are guesses | Left for you to listen to |
| Narration density | 690 words in 33 lines covers about 215 of 344 seconds, which is on the dense side | Left for you to judge; the long mechanism stretches stay quiet |
| Known limits | A coarse Scilly coastline from 10 m data, the hopper pin passing in front of the lever finger, a flat band for the Act III eyepiece sky, an unexplained hairline at the edge of the trial zoom, and no translucent light cones in Act I | Listed in the project notes as accepted |
What it taught
Five things the log says
Two films from one chat
The wordless original was rendered at 22:08 and, on your request at 22:14, a narrated edition followed at 22:24, built as a sibling project that reuses the original’s picture code and swaps only the audio.
The picture and the sound read one cue file
The hopper beat, the H4 beat, Io’s eclipse, the burin cuts and the sweeps all take their times from
src/cues.js. In the rendered audio the hopper ticks landed within 3 ms of those cues and all 180 H4 ticks within 1 ms.A representative slice, then the rest
The hopper, a mechanism sample, was taken through a draft and two named enhancement passes before the other acts were built, and the log records the faults found at each step.
Cursor kept only part of the chat
The message records begin at 22:21, an hour and a half after the request, so the tool-call row starts there; the code-writing row covers the whole session from the first edit at 20:53.
The model was Claude, the tool was Cursor
Cursor recorded claude-sonnet-5-5 for this chat. It logged context, 203,080 of 300,000 tokens at the end, and no token usage, so there is no bill to report.
Method
How these figures were measured
Measured from Cursor's own stores: the chat's record in the global state.vscdb (one record per message, with its creation time and the tool it called) and the AI-code tracking database, which timestamps every line of code the agent wrote. User message times come from the chat transcript. The chat has 526 message records from 22:21 on; the opening 90 minutes of the chat are not in Cursor’s store, so the first part of the timeline comes from the code-tracking timestamps alone.
There is no cost on this page. Cursor writes zero for input and output tokens in these records and keeps only the size of the context, so the list-price figures used on the other pages cannot be worked out. The model name is the one Cursor recorded.
Times are UK local time (BST, UTC+1). Local-machine marks are the modification times of the generated files. The sync checks, level figures, review findings and known limits come from the project’s review log and the agent’s final reports in the chat transcript.