Kinematograph year book (1939)

Equipment and Technique in 1938. 281 Strong Electric Distributors. — Since the introduction of A.C. arc lamps to the British market and following the installations made in the early part of 1938, great strides have been made by Messrs. Strong Electric Distributors, Ltd., and at the close of the year installations numbering well over 50 have been completed. Their programme for 1939 is formidable and ambitious, as this enterprising concern headed by W. StanleyAldrich have laid down plant for the manufacture of Strong inductors in this country to cover a matter of four installations a week. The Strong A.C. equipment is performing remarkably efficient service in a number of good-sized theatres, amongst which are the Gloria, Derby,; the Tudor, Nottingham ; the Regal, Caversham ; Astoria, Baldock, etc., etc., in all cases great saving and high screen illumination are admitted to have been effected. The current consumption is very low, varying from 2 to 2\ units an hour according to the characteristics of the particular theatre wherein it is installed. Carbon consumption is reasonably low as compared with ordinary D.C. H.I. arc lamps, though it might be found to be slightly above the carbon costs of a D.C. low intensity. The all-round screen illumination is in the region of four times that of average D.C. low intensity and on a par with the average modern D.C. Suprex H.I. working at 45 amperes. In theatres where the earlier type of H.I. reflector arc lamps are used at from 65/80 amps., it is found that a considerable increase in screen illumination is obtained with the Strong A.C. equipment. In view of the great amount of incidental equipment with which the Strong A.C. arc lamp dispenses and the small amount of wiring required for installation, the A.C. question is one which can be seriously considered by all exhibitors whose theatres are within the A.C. scope — i.e., auditoriums seating 1,000 to 1,500 with screens 18 ft. to 22 ft. in width. Walturdaw. — Two new high intensity lamps of Zeiss Ikon design and manufacture have been introduced during this year ; they are, namely, the Magnasol II and Magnasol III lamps, which are constructed to obtain the highest light fluxes in an economical way and to produce a solid construction to give full working security. The Magnasol II lamp is designed for load of from 35 to 65 amp. with carbons burning in the horizontal position without condenser ; it has a mirror of 356 mm. diameter of the already popular Kinesol curvature. The Magnasol III is designed for loads of 70 to 120 amp. with carbons burning in an angular position, employing the same Kinesol curvature mirror in conjunction with 170-mm. diameter condenser. In the case of the Magnasol III these lamps are provided with fan-cooled mirror mounts and also tempex glass spray guards. Both these new lamps possess automatic feed control in which the positive carbon feed rate can be adjusted within the wide limits of from less than 1 mm. in advance in a minute up to 10 mm., which means that the feed proportion of the positive and negative carbons can be adapted to any combination of carbon and any load. Philips Cine-Sonor (Philips Lamps, Ltd.). — Details of the high-pressure mercury vapour lamp for projection purposes, which, having successfully passed actual operating tests, is shortly to be placed on the market, reveal the efficiency of the new light source and the simplicity of its installation. The outstanding characteristics of the new lamp are claimed to be its tremendous light output, small dimensions and almost entire absence of heat. To describe it briefly, the lamp proper is a quartz tube, 1\ in. long and of quite small diameter, with an electrode sealed into each end of the tube. The discharge strikes immediately as soon as the power is applied, and the