- Binnacle
A binnacle is a case or box on the
deck of aship , generally mounted in front of thehelmsman ,in which navigational instruments are placed for easy and quick reference as well as to protect the delicate instruments.A binnacle may be subdivided into sections and its contents typically includeone or morecompass es and aoil lamp or other light source. Other devices suchas a sand timer for estimating speed may have been stored in the binnacle as well.The construction of many early binnacles used nails (mid 1700s), which were later discovered to cause
magnetic deviation s in compass readings. As the development of the compass and understanding of magnetism progressed greater attention was given to binnacle construction to avoid compass disturbances caused by iron.With the introduction of iron-clad ships the magnetic deviation observed in compasses became more severe. Methods of compensation by arranging iron or magnetic objects near the binnacle were developed. In 1854 a new type of binnacle was patented by John Gray of Liverpool which directly incorporated adjustable correcting magnets on screws or rack and pinions. This was improved again when
Lord Kelvin patented in the 1880s another system of compass and which incorporated two compensating magnets.The ship's Binnacle List is the medical department's report of personnel at sick bay, excused from that day's duty. [http://www.tpub.com/content/medical/14295/css/14295_398.htm]
Etymology
Before 18th century "bittacle", through Span."bitacula", from Lat. "habitaculum", a little dwelling
References
*1911
*Alan Gurney, "Compass: A Story of Exploration and Innovation", W.W. Norton & Company, 2004, ISBN 0-393-32713-2.
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