[33] It is a good weather glass--to be suspended on or near the upper deck, for easy reference;--and is unlikely to be injured by mere concussion of air, or vibration of wood, when guns are fired. [34] Allowing 0,0011 of an inch for each foot. [35] The manufacture of these useful auxiliary instruments (all French originally) has increased much latterly: and now the patent has expired. They might be so improved so to be worth more than double their present value. [36] Like the sun's edge or limb, touching the sea horizon, as seen inverted when using a sextant. End of Project Gutenberg's Barometer and Weather Guide, by Robert Fitzroy