quintant

plural quintants

1. historicalAn instrument used for measuring angular distance, capable of measuring angles of up to 72 or 144 degrees.

   In former days octants, quintants and quadrants were in general use. The only basic difference between these instruments and the sextant is in the length of the arc.

   1944, Bart J[an] Bok, Frances W[oodworth] Wright, Basic Marine Navigation, Boston, M.A.; […]: Houghton Mifflin Company, page 242

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   McCarthy, it may be noted, had escaped when the Andamans were invaded, in a twelve-person party aboard a launch. He had navigated the party as far as Ceylon using a hydrographic quintant in lieu of a magnetic compass.

   1978, Ian Trenowden, Operations Most Secret, London: William Kimber, page 62

   Midstream at the treacherous Sankrail and Panchpara stretches of the river the crew set about the task of preserving safe passage with austerity technologies. Accuracy was ensured by combining the ancient quintant and chart used for two hundred years on the river and an aging echo-sounder.

   2015, Laura Bear, Navigating Austerity: Currents of Debt Along a South Asian River, Stanford, C.A.: Stanford University Press, →ISBN, page 3

2. rareA fifth of a circle.

   The dome rests on five pylons, equally spaced at 72°; two of the five quintants embrace the office building.

   1959 September, “Moving Day for the American Society for Metals”, in Metal Progress, volume 76, number 3, Metals Park, O.H.: American Society for Metals, →ISSN, →OCLC, page 64-C

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   Sectors are particularly denominated from the proportional part of the circle they contain; thus, a quadrant contains a 4th part of the circle; a quintant, the 5th part; a sextant, the 6th part; an octant, the 8th part; &c.

   1819, Robert Patterson, A Treatise of Practical Arithmetic: Intended for the Use of Schools; In Two Parts, Pittsburgh, P.A.: […] R. Patterson and Lambdin, page 85

   An inspection of this diagram will show at once that as far as spine locomotion is concerned Lytechinus may creep in any direction with apparent indifference. That this indifference is probably a real one is shown more clearly in Fig. 2 in which is plotted for each of the five ambulacral quintants the instances of creeping falling within each one.

   1936, G[eorge] H[oward] Parker, Direction and Means of Locomotion in the Regular Sea-urchin Lytechinus, page 201