23.68 G.Francia, Installations pilotes pour centrales solaires, (C.O.M.P.L.E.S. Rencontre de Genes, Commsion centrale, Commissione de Conversion Thermodynamique, 20-25 mai 1968). The mirror-holder rod that coincides with the unequal side of the isosceles triangle, the opposite apex of which is the centre of the circular sector. The fulcrum of the support (left) is fixed when assembling in the way described in fig. 23.068.2. The kinematic motion is around its axle parallel to Earth's axis at a constant speed; the change of declination is obtained, presently by hand, by operating the knurled wheel which controls the sector.