Uniform Regulations, 1864
All shoulder straps, except for gunners, boatswains, carpenters,
and sailmakers, are to be of navy-blue cloth, four inches and
a quarter long, and one inch and a half wide, including the border,
which is to be a quarter of an inch wide, and embroidered in gold.
The centre and end ornaments, or distinctions of the line and staff, and indications of rank, are to be embroidered in gold or in silver, as hereinafter designated, and are to be as follows:
Plain centre circle, five-sixths inch in diameter, with letter in relief.
Yellow centre, with letter P in old English in relief, in Silver, with leaf at each end, embroidered in Silver.
FOR PROFESSORS OF LESS THAN TWELVE YEARS.
Plain centre circle, five-sixths inch in diameter, with letter in relief. Border one-fourth inch wide.
Yellow centre, with letter P in old English, in Silver, and leaf at each end to be embroidered in Gold.
Bars, two-tenths inch wide, one-half inch long. Bars, four-tenths inch from end of Strap. Space between Bars one-tenth inch.
Letter S in old English, embroidered in Silver, in centre, and two bars at each end embroidered in Gold.
Source: Uniform for Officers of the United States Navy, As Prescribed in Regulations for the Uniform of the U.S. Navy, Jan. 28, 1864. Tomes, Melvain & Co., 6 Maiden Lane, New York. Entered according to Act of Congress, in the year 1864, BY TOMES, MELVAIN & CO., in the Clerk's Office of the District Court of the United States, in and for the Southern District of New-York. The text is reproduced here exactly as in the original, following the original use of capitalization and italics.