The first of five clues. Each one below gives a little more away.
I always agree with you about which way is forward, and I am always slightly wrong.
The Chinese first used me to arrange furniture, not to travel.
The point I aim at wanders about fifty kilometres a year.
Hold me near iron and I will lie to you.
A trembling needle that points north.
Compass
Magnetic north sits under the Arctic Ocean and wanders. Since the 1990s it has been sprinting towards Siberia.
The Chinese were using lodestone for centuries before anyone pointed it at the sea — the earliest instruments were divination boards for aligning buildings. Shen Kuo, writing in 1088, is the first to describe a magnetised needle used for navigation, and to notice that it does not point at true north. That error, called declination, varies by place and by year, which is why nautical charts print a correction that expires. The magnetic pole has been moving faster lately, drifting from Canada toward Siberia at around fifty kilometres a year, forcing early updates to the global model aircraft rely on.
Reading five clues at once is not the game. In the real thing they arrive one at a time and every wrong guess costs an hour. Play mystery #19 · today's mystery · the vault
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