A study of the weathering resistance of vitreous enameled architectural panels \Was begun by the National Bureau of Standards in 1939. The study involves t,64 one-foot-square panels, representing 14 types of enamel and a like number ~f 4-by 6-in. laboratory specimens. At the end of the first year of exposure at 1C0ur locations selected for different climatic conditions, over half of the panels ~howed no visible weathering effect, and in no case did weathering produce any ~ailure of the enamel to protect the underlying metal from rusting.The full-mat enamels were found unsuited for architectural use where appearance is important, because of fading and of difficulty in cleaning. Mild fading, found on some of the non-acid-resistant colored enamels, was associated with a minute pitting of the enamel surface, probably caused by the presence of acidforming gases in the atmosphere. The enamels of high acid resistance did not s how this effect.

Detecting the site of an erasure on a questioned document may ultimately lead to the discovery of a theft involving millions of dollars. Document examiners, particularly those who evaluate evidence in criminal matters, are frequently faced with problems involving erasures. A method of detecting the site of a mechanical abrasion made by a rubber-type eraser was tested and evaluated in comparison with the success of other methods. The method uses a chemical powder and is extremely sensitive in detecting rubber erasures even in cases where more frequently used methods had failed. Several shortcomings of the powder method were discovered during the period of evaluation and these disadvantages are discussed.

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The importance of the unconscious habit of shading within an individual's handwriting and its relationship to handwriting identification is illustrated by a case study. The subtle variations of pen pressure within handwriting should always be a integral part of any forensic handwriting comparison. A thoughtful evaluation of seemingly unrelated, random movements within a questioned signature may often be deciphered as a carefully executed series of related movements with consistent pressure variations. If their sequence and relevance within the signature are correctly interpreted, these variations and movements can be of the utmost importance in a final determination of genuineness.

Document examiners are often asked to examine copies in lieu of originals. Although copies frequently limit the forensic examination, they sometimes provide evidence that greatly increases their investigative importance and prosecutorial value. This paper presents one such case recently examined at the Southern Region Crime Laboratory of the U.S. Postal Inspection Service. The case involved large numbers of office machine copies of gasoline sales receipts used to support a series of false claims. Laboratory examinations of the copies disclosed evidence that led to their positive association with the original and with several previous generations of copies produced by a variety of reproductive methods.