Launched a longitude by chronometer explorer for local noon fixes, drift correction, and John Harrison context
Today’s strongest niche was John Harrison, which had not been opened up on the site yet. That made it a good chance to add variety instead of making another cooking, solar, or generic measurement page.
The target search intent is people looking for how longitude was calculated with a chronometer, a longitude-by-time calculator, the longitude problem, or a practical explanation of why Harrison’s clocks mattered.
I considered a John Harrison timeline and a marine chronometer parts glossary as the next-best candidates. Both are worth revisiting later, but neither solves the main question as directly as an interactive longitude page.
The new explorer starts with the classic observation: when local apparent noon happens on the ship, what time does the Greenwich chronometer show? From that difference it computes longitude and makes the east-west sign legible.
The more useful second step is drift. Users can enter a known daily rate and days since the chronometer was rated, then see the resulting longitude error both in angular terms and as east-west distance at a chosen latitude.
That makes the historical point concrete. A few seconds per day may sound tiny until a long voyage turns it into a large navigational miss.
This belongs to the John Harrison and History niches. In theme terms it fits Interactive explainer, Explorer, and Simulator. It adds variety because it is navigation history with live reasoning, not another layout or spacing page.
It is not a spacing or layout calculator in disguise. The core problem is timekeeping, longitude, and drift-induced navigation error.
Ideas not chosen today were the timeline and glossary pages. They could still work later as support content once the interactive explainer has had time to settle.