Sundial · Self-assembly
Equatorial Sundial Kit
A small wooden equatorial sundial you assemble yourself, with a latitude plate and a compass built into the base. Set its angle to where you live and it tells the time from the Sun — and shows you, physically, why the Earth’s tilt matters.
- Finished size
- 75 × 85 × 105 mm
- Material
- Wood
- Assembly
- Self-assembly
- SKU
- NS-201
What it is
An equatorial sundial is the clearest of all sundials to understand, because its geometry is the sky’s geometry made solid. The rod — the gnomon — is set parallel to the Earth’s axis, so it points at the celestial pole. The dial it casts its shadow onto sits in the plane of the celestial equator, at right angles to that rod. Once it is aligned, the shadow sweeps the dial at exactly the rate the Earth turns. This kit gives you the two things you need to set it up properly: a graduated latitude plate to fix the tilt, and a compass in the base to find north. Assembling it is a short job; understanding why the angles are what they are is the part that stays with you.
What it actually teaches
- Why the gnomon must be tilted to your own latitude: it has to lie parallel to the Earth’s axis, and that angle above the horizon IS your latitude. The kit’s latitude plate is graduated 0–40°, which covers every part of India — Kanyakumari sits near 8°N and the top of Ladakh near 37°N.
- Why an equatorial dial has evenly spaced hour lines — exactly 15° per hour — while horizontal and vertical sundials do not. The Earth turns 360° in 24 hours, and this dial faces that rotation squarely.
- Why the dial needs two faces: the Sun shines on the upper side from the March equinox to September, and on the underside for the other half of the year.
- That the Sun keeps its own time, and it is not the time on your phone.
- How to read an hour ring twice over: the dial carries the 24 hours in numerals and the twelve traditional Chinese double-hours beside them, which is a neat demonstration that dividing the day is a convention rather than a law of nature.
What it will not do
A sundial that agreed exactly with your phone would be a clock with a shadow on it. Here is where the difference comes from.
- It will not agree with your clock, and that is not a fault. A sundial reads apparent solar time. Indian Standard Time is set by the 82.5°E meridian, so from Delhi (77.2°E) the Sun runs roughly 21 minutes behind IST before any other correction.
- On top of that, the equation of time shifts the Sun up to about 16 minutes either side of the average across the year. Expect a reading within half an hour of your clock once both corrections are applied — not within a minute.
- It needs direct sun, a level surface and an honest north alignment. The built-in compass points at magnetic north — which, as it happens, is close to true north across India: the country sits near the line of zero declination, so the error is a degree or two rather than the ten or more you would fight in parts of Europe or North America. Worth looking up for your own city, since a small alignment error costs you minutes.
- Around the equinoxes the Sun sits almost in the plane of the dial, so for a few days either side the shadow grazes the face and is hard to read.
- It is a wooden kit, not a precision instrument. Treat it as a demonstration you can hold, which is what makes it worth having.
In the box
- 1 × wooden equatorial sundial kit, unassembled
- Latitude adjustment plate, graduated 0–40°
- Compass, seated in the base
Before you buy
- Contains small parts. Not suitable for children under three.
- Wood is a natural material — grain and finish vary between pieces.
- Finished size is approximately 75 × 85 × 105 mm.
- The dial is cut for the Northern Hemisphere and marked as such, which is what you want anywhere in India.
- Hour markings are in numerals and Chinese characters. The numerals are all you need to read it.
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