meridian circlen.

a1544 R. Barlow tr. M. Fernández de Enciso Brief Summe Geogr. (1932) 3 The byggest cyrcles be the equynoctiall, zodiac,..meridian and oryȝon.]

c1550 Complaynt Scotl. (1979) vi. 37 It sal declair the eleuatione of the polis, and the lynis parallelis, and the meridian circlis.

1559 W. Cuningham Cosmogr. Glasse 146 Untill she commeth to the Meridian Circle, and is full South.

1728 Philos. Trans. 1726–7 (Royal Soc.) 34 149 The Center appears to have been..about 2 or 3 [Degrees] distant from the Meridian Circle towards the East.

1881 J. C. Maxwell Treat. Electr. & Magnetism (ed. 2) I. i. 198 The spherical surface is divided into..quadrilaterals or tesseræ..bounded by meridian circles and parallels of latitude.

1992 Trans. Amer. Math. Soc. 331 144 For each j = 1,…, r, λ_j is a longitude circle of the solid handlebody N(L_j), μ_j a meridian circle of N(L_j), [etc.].

1809 Philos. Trans. (Royal Soc.) 99 115 The method, as practised on a late occasion, in the dividing of a four feet meridian circle now the property of Stephen Groombridge, Esq.

1833 J. F. W. Herschel Astronomy ii. §140. 91 Such an instrument is called a transit circle, or a meridian circle, and serves for the simultaneous determination of the right ascensions and polar distances of the objects observed with it.

1934 H. S. Jones Gen. Astron. (new ed.) iv. 82 In the meridian circle, the framework carrying the horizontal wire and the system of vertical wires is moveable in the meridian at right angles to the telescope axis.

1992 S. P. Maran Astron. & Astrophysics Encycl. 36/2 The workhorse for the measurement of the positions of bright stars at optical wavelengths is the meridian circle.