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Tests on Rock from Cobb River Dam-site. —Comprehensive tests of the physical properties of foundation rock from the Cobb River dam-site have been completed. North Island Ironsands.—The separation by mechanical or simple chemical means of titanium from the iron in the titaniferous magnetite of the North Island west coast ironsands has been investigated by x-ray crystallographic technique. The minerals are so intimately mixed that there is little hope of finding any economic means of separating them mechanically. Building Research Projects (See Building Research report, p. 8.) Instrumentation Laboratory Clinical Sphygmograph.—Development work is proceeding on an apparatus designed to give a visible and permanent record of changes in blood-pressure in the human subject during the course of surgical procedures under general anaesthesia. Other Projects.—The following is a selection of the instruments developed or investigated: frost-alarm, photofinish equipment for racing, beehive-temperature recorder, and aircraft-weighing machine. General Calibration and Testing of Instruments. —This Laboratory has had an increasing volume of work of this category because no substantial diversion of commercial instrument-repair has been possible as yet to private firms. The latter is precluded because of the somewhat specialized equipment and techniques involved. Standards Laboratory The following standards are at present being set up : electrical, linear, mass, temperature, photometric measurements and standards, and the barometric standard. The officer in charge of this section returned from overseas, and a start has been made in developing techniques and methods associated with Standards practice. Orders and estimates are being prepared to build up equipment to a level consistent with the Standards legislation, 1945. Design Section Major projects handled by this Section included river-stage recorder (for recording river-levels), vehicle-volume counter, portable chronograph, sun camera, fruit-bud apparatus (to test frosting temperatures), ultra-centrifuge, and mechanical high-vacuum pump (for fish-liver-oil distillation). In addition to the above, a number of smaller projects have been handled and a large amount of routine drawing and tracing work undertaken. Electrical, Electronics, and Acoustics Laboratory The work of this Laboratory falls into three main categories : development of electrical and electronic aids to engineering and industry, instrumentation for reserach and survey work, and routine electrical testing. Aids to Engineering and Industry. —A cross-cut of the work includes construction of grass-seed and flax-fibre moisture meters, sealing of pliofilm bags using radio frequency di-electric heating, and measurement of thickness and location of flaws in metal by supersonics.

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