A candle clock is much simpler to make than other types of time-keeping devices.
The Encyclopedia Britannica reports that candle clocks have been in use since the late ninth century AD. Some historians believe that their use dates back even further. King Alfred the Great of England used candle clocks to segment his daily activities. You can make a candle with hour marks to divide your day just as King Alfred did or to show the passage of time during an important event. All that it requires is making two candles and testing one to see how much of the candle burns in an hour.
Instructions
Making the Candle
1. Melt the candle wax with a wax heater. Stir the wax frequently with a wooden stir stick during the melting process.
2. Insert a wax thermometer directly into the wax. The manufacturer of the wax should have specified the proper melting temperature for the wax. Remove the wax from the heat once it has reached this temperature.
3. Grease the inside of the candle molds with cooking spray or vegetable oil. The lubricant must reach the bottom of the molds.
4. Pour the wax into the molds, but do not fill them to the top. Gently tap the sides of the molds after pouring so that any air bubbles in the wax rise to the surface.
5. Insert the wicks into the molds. At least an inch of the wicks should be left at the top.
6. Remove the candles from the molds and trim the wicks to a shorter length if desired. The candles must be cooled completely before being removed from the molds.
Creating Hour Marks
7. Burn one of the finished candles for an hour and then blow it out.
8. Lay the burned and unburned candles side by side on a flat surface. Alternatively, stand them up beside each other in candle holders. The bottoms of the candles should be aligned in order to accomplish proper time marking.
9. Mark the height of the burned candle on the unburned candle with a black permanent marker so that you will be able to see the marks clearly.
10. Measure the distance from the top of the unburned candle to the mark that you made. Take note of this measurement, as you will need it to make the rest of the hour marks on the candle.
11. Draw more marks that are the same distance apart as the measurement you made in Step 4. Continue to draw the marks until you reach the end of the candle.