(_g_) The frame shall be constructed with jointed bars for interpupillary adjustment.
5. _Service field glass, type B._--(_a_) The requirements of part 4, service field glass, type A, of this specification, shall be followed in the design and construction of the type B glass in so far as applicable.
(_b_) Power: The lower power shall be approximately 4½ and the high 6½ diameters.
(_c_) Object lenses: These shall have a clear aperture of at least 1¾ inches diameter.
(_d_) Case: Case and carrying strap shall be furnished as required in part 4 of this specification.
(_e_) This glass shall be constructed with jointed bars for interpupillary adjustment.
(_f_) The sunshade, when drawn out, shall project not less than three-eighths of an inch and not more than 1 inch beyond the edge of the cell.
6. _Marking._--Glasses furnished under this specification shall be marked on one barrel with the words "Signal Corps, U. S. Army," and on the other barrel "Serial No. ----." Serial numbers will be furnished with the order. If not furnished the contractor at the time the order is placed, the Disbursing Officer of the Signal Corps should be called upon for same, and the numbers and other marking placed on the glasses prior to the delivery of the order.
JAMES ALLEN, _Brigadier-General, Chief Signal Officer of the Army_.
SIGNAL OFFICE, _Electric and Telegraph Division_.
There is no figure 25 in this text. The numbering goes from figure 24 to figure 26.
Page 23, "porportions" changed to "proportions" (in proper proportions)
Page 106, "engineeer" changed to "engineer" (a French engineer)
Page 126, opening bracket added to subtitle ([Revised February 10, 1910.])
End of the Project Gutenberg EBook of Visual Signaling, by Signal Corps United States Army