‖ sesquialter, a. (n.)
(sɛskwɪˈæltə(r))
[L., f. sesqui- (see prec.) + alter second. For the formation cf. ON. hálfr annarr, OE. óþer healf, G. anderthalb.]
1. Of a proportion: That is as 1½ is to 1. Of an object: Proportionate to another object as 1½ is to 1; that is such a multiple of.
| 1570 Dee Math. Pref. c j b, A Cylinder, whose heith, and Diameter of his base, is æquall to the Diameter of the Sphære, is Sesquialter to the same Sphære. 1598 Florio, Hemiolio, an arithmeticall proportion called Sesquialter or Sesquiplex, which is so much, and halfe so much againe. 1641 H. L'Estrange God's Sabbath 119 This would by sesquialter proportion exceed all the rest. 1660 Barrow Euclid iv. xi. Schol., Isosceles triangle, whose angles at the base are multiples sesquialter of those at the top. 1698 Phil. Trans. XX. 81 We assign to a Fifth..the Sesquialter Proportion (or that of 3 to 2). 1711 H. Needler in J. Duncombe Lett. (1773) I. 90, 6 is only sesquialter of 4. 1715 Cheyne Philos. Princ. i. 222 In all the Revolutions of the Planets about the Sun,..the periodical Times is [sic] in a Sesquialter Proportion to the middle Distances. 1784 J. Keeble Harmonics 29 The sesquialter chromatic. 1846 Penny Cycl. Suppl. II. 369/2 The following ratios are super⁓particular: 15 to 10, which is sesquialter. |
† b. Mus. = sesquialtera 1 b.
| 1704 J. Harris Lex. Techn. s.v. Time, Sesquialter Proportion, which signifies a Triple Measure of three Notes, to two such like Notes of the Common Time. |
2. = sesquialtera 2.
| 1841 Penny Cycl. XXI. 293/2 Sometimes the Mixture stop is considered as part of the Sesquialter. 1846 Ibid. Suppl. II. 369/2 The sesquialter stop of an organ. |