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. Dahlgren. Dahlgren Laboratory. Development of the Armor and Projectile Laboratory 73. Spectographic equipment (including Dr. Sawyer's original spectrograph). Car bottom heat-treating Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original McCollum, Kenneth G. Dahlgren, Va. : Naval Surface Weapons Center
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