April 2, 1918 - Mary works at the P.B.X.

For the first half of 1918 Mary worked as a telephone operator, presumably during this time only for A.T.& T., mostly it appears on the P.B.X., private branch exchange.  A private branch exchange is an internal telephone switchboard, calls received by a company being directed to the central switchboard and from there redirected to various extensions within the institution.  At the time Mary was working, this was all done manually.  On different occasions Mary mentions P.B.X., A.T.&T. and working with "cords".

Young boys were first to be hired as switchboard operators in the late 19th century.  It was soon found that women were more suited for the work.  According to Women's Occupations Through Seven Decades, by 1910 more than 90% of telephone operators were women, there being over 88,000 women telephone operators by that year, increasing to over 178,000 by 1920.