the exhaust gases so that the radioactive substances in the samples could be removed. A Beckman Mcdel DU spectrophotometer was used to analyse for some of the minor constituents of coral and sea water, 2.3.7 X-ray Diffraction Appt ratus A General Zlectric XRD-3 X-ray diffraction unit was used in the X-ray analysis of Project 2.6a samples. The essential components of this unit are a high-intensity sealed-off X-ray tube energized by a voltage-stabllized power supply, 4 collimating system which permits the use of slit or pinhole collimators, an X-ray camera using the Straumanis method of film losding, and two types of sample mounts (rotating and oscillating wedge). The samples were fine, crystalline materials. Some were indi- vidual pellets of 1 to 2 cu mm, others were friable powders. All were in a very satisfactory state for X-ray cnalysis. For individual particle analysis, a pellet of anproximately 1 mn long and 9.5 mm in diameter was cemented to the end of a fine glass fiber, supported cn the rotating sample mount with the particle centerad in the path of a collimated beam of filtered copper K, radiation. The diffracted rays were registered on film. Normal xposure time was 7 hr. The friable material was crushed to reduce the large aggregates to smaller uniform size powder, which vi: sacked into the shape of a wedge and mounted on the oscillating mount. The edge of the wedge wes adjusted to intercevt one-half of a slitecnollimated beam of filtered copper Kq radiation. The diffracted rays were registered on film during a 1-1/2 hr exposure. A comparator26/ was used to compere the diffraction patterns from fallout with those from coralsand collected near the site of the deto- nation. 203.8 Petrogravnic Microscoze A Bausch and Lomb Petrographic Microscope, model WL 3238 with a Leitz 4-axis universal stage was used to examine sections of radioactive particlas. 2.3.9 Ion Exchange Equipment Ion exchange columns and assessory equipment were used for the seperation of rare earth fission products. The column was eluted with lactate at a controlled pH at a temoerature of 87°C, collected in small fractions by a fraction collector. 203210 The effluent was Film Coating Apparatus This equipment was developed to produce specially coated water droplet sensitive 35am film, The apparatus consists of a variable speed drive motor which pulled the film through a series of etching, washing, ami coating baths and thence through a thermal drying chamber to a reel onto which the film was wound in 500-ft lengths. ‘The film was 24