32 EHOMBOIIEDEAL SYSTEM. -Lne signs ot tanT, tanD will Jm rs iss 4 —s tx*: of th ” e pole! of sin±r = sin60°sinT. The distance between nr... 4. t has the indices 4- k -b b , 7° a ^J acent poles, one of whicli — h — I, will be iso 0 — V a ^ le ot her the indices — h, po = 90 o , P a b nd a if y H P w? /f ^l 6 , form hM > w here k + h + I = o, polesofM,haYin g Z^Xfs1:T bet ween any two adjacent t fl n 111 = ^3 lc ~ l . 2k — k — I' having the 8t indices ar + an T two P oles of the form kkl, h, k, I, or neither of tiL ■ r + V*?, 11 ’ K ’ L orT > according as symbols of the two nJ ln dices, holds the same place in the from in ■ D ttle es > T the distance of either of the poles the nearest pole of an ^ P°^ c °t the form 100 from tended at in by „ * Z U1; 2d ’ 2 *> 2 * tlie “gl™ ™b- 120°. Then ’ L ’ he au S le subtended by v will bo tanT + (l—ky + (k — &) a 1? ' TTTk + i tanO = ^3 h ~ 1 2 h — k — V tan^ = ^/a_ 1 ~ h 2k - I - k’ tan,// = ,/a. A A 21 — h — k‘ sm| H _ sin0sint, 8in , K _ sin ^ inT) 127 If Sm|L = Bhl * B[aT ’ * inl * Y = poles of the form hkk be pIvo^™ a , n ^ two three equidistant ^ hl'CH. WH nntTn given, we have sin|v = sin eo° sin t, tanx = wtanD , (k ~ ± m (A + 2k),