Log glass
The log glass was used in conjuntion with a log and line in order to time the period during which the line was allowed to unroll from a reel and so estimate the ship's speed. Usually this was for a period of up to half a minute. This brass log glass timed a period of 14 seconds and has '14 SEC' inscribed on it.
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Object details
| ID: | NAV0742 |
|---|---|
| Collection: | Astronomical and navigational instruments |
| Type: | Log glass |
| Display location: | Not on display |
| Creator: | Unknown |
| Date made: | circa 1900 |
| Credit: | National Maritime Museum, Greenwich, London |
| Measurements: | Overall: 82 x 29 mm |