New York: C. C. Shelley 1891. 50,  pages. 8vo (5 7/8 x 9 1/8 inches). Publisher's tan printed wrappers. Tearing, creasing and soiling to the covers. Portions of spine paper perished. Both errata and folding organizational chart of a "mid-sized station" present. A well used copy
27, [1-blank] pages. 8vo. Light grey printed wrappers. Front wrapper detached, rear creased. Lower corners all bent. A worn copy.
Both pamphlets are ex-library "The Edward Caldwell Electrical Collection, Knox College, 1950" with associated red ink stamp. Fair. Wraps. 
In essence a pamphlet with suggestions on the financial management of Central Power Stations and printed forms to support this work. The first volume is based on a series of articles prepared by Foster at the request of the publication "The Electrical Engineer" and published in that forum during 1891. The various forms referred to were published separately as well, and made available by C. C. Shelley with the note:
"The use of these blanks will be found of the greatest benefit in promoting the economical management of electric light and power stations. The undersigned [ C. C. Shelley ] has made exclusive arrangements for their publication, and will be glad to furnish them in any quantity." They also note the impending collection of articles also offered here.
Pearl Street Station was the first to supply large scale DC power to lower Manhattan in New York City in 1882. Alternating current didn't appear until around 1886 in America. With rapid technological changes and financial stakes, tools to help manage these stations were no doubt in demand.
OCLC records 15 copies of the summary pamphlet, and none of the Central Station Blanks pamphlet as of this writing.