Electrical Engineer, April 28, 1898, page 468-469:
1898 Electrical Exhibition

Preparations  at  the  Electrical  Exhibition

    Madison Square Garden passed into the hands of the Electrical Exhibition management at midnight on Saturday, and an army of workman at once began, under the direction of Mr. Marcus Nathan and the officials of the Garden, to get the vast arena in order...

The  Telephone  at  the  Exhibition.

    The New York Telephone Company will make an admirable exhibit illustrative of the operation of the telephone system of this city. There will be shown specimens of the latest styles of telephone apparatus and silence booths for the equipment of public and private telephone stations. Pretty nearly everybody is more or less directly interested in the telephone service nowadays, though few know just how it works. The New York Telephone Company's exhibit will give visitors to the show a very fair idea of just how the service does work as part of the exhibit will be a switchboard in actual operation, which will serve stations at various points in the Exposition building. Trunk lines will run from the Exposition switchboard to one of the main exchanges, so that the stations in the Exposition may not only be connected directly to each other, but also to any station in the city or in any part of the country reached by the telephone systems of the New York, the New York and New Jersey and the American Telephone and Telegraph Companies.
    In short, this part of the exhibit will be a working specimen of the Private Branch Exchange System, which has been so largely adopted by big business houses of all classes since its introduction by the New York Telephone Company a year or two ago.
    Arrangements are also making for a separate telephone feature which will be the transmission of music from various New York theatres and out of town points every evening during the month of the Exposition. The Exposition Company, the American Telephone and Telegraph Company and the New York Telephone Company are working jointly in the production of this attraction, which is sure to be popular with the general public.
May 12, 1898, page 522:

    Adjoining the Society booth, the "Theatrophone" is in full swing, being the telephonic service from the theatres handled by the New York Telephone Company. Multitudes gather around nightly to hear the songs, marches, applause, etc., and the various exhibitors in the Garden have already worked out a pretty accurate time table, of the leading specialties. and a general movement from inside the booths to the long board indicates that something good is just about to be on tap.
May 12, 1898, page 524:

The  New  York  Telephone  Co.'s  Exhibition  Exchange  and  Display.
IMMEDIATELY upon entering the Garden the visitor catches sight of the splendid exhibit of the New York Telephone Company, which is located near the Madison avenue entrance and is intended to illustrate a private branch exchange system and a model pay station. In the company's space is placed a standard switchboard to which are connected telephones installed in the working departments of the exhibition and in the booths of the exhibitors throughout the exhibition hall. The switchboard also has a system of "trunk lines" connecting with the general telephone system. The various exhibitors are enabled to communicate with each other or with any station in the New York system. The Private Branch Exchange System, shown here, is adapted to large establishments of all sorts. A private switchboard serves as a connecting point for the trunk lines which run to the nearest exchange of the general system, and the lines which branch out from the switchboard to the various offices or departments of the subscriber's premises. This subdivision of the telephone service gives the very acme of efficiency in the conduct of the telephone traffic of a busy establishment. There is no confusion, no delay, no lost calls, and a large volume of traffic can be disposed of without friction. The Branch Exchange System is in use by about 200 large business houses of all classes. In no case has it failed to give complete satisfaction, and to produce an improvement in the service, conducted before with insufficient facilities at the subscriber's end.
    The company also have on exhibition four "silence" booths similar to those supplied for the equipment of public or private telephone stations in New York; they are equipped with the different styles of telephone sets used by the New York Telephone Company. Another leading feature of the exhibition is the Theatrophone installed by the company. This consists of a novel single plug switchboard which has connected to it five prominent theatres enabling sixty persons to listen to the plays at any one time. Numerous telephone boys are in attendance and all questions about the working of the exchange are cheerfully answered by Mr. Herbert Laws Webb, to whom is due most of the credit for this superb installation, and Messrs. Wm. E. Huntington and S. D. Brewster, who are indefatigable in their intelligent efforts to serve exhibitors and inform the public.
1898 New York Telephone Company Display

June 2, 1898, page 614:
Running  Notes  on  the  Electrical  Exhibition

    The telephone had its share in the successes of the week, particularly in its long distance work. Three or four of the comic operas playing in the city are brought to the Theatrophone board, but not satisfied with that the New York Telephone Co. introduced on Monday night a concert by the famous Lauder Orchestra then playing in the Palm Garden at Milwaukee, about 1,100 miles away. In spite of the drenching rain, the music came through very satisfactorily to the delight of a large number of auditors. On Wednesday evening Sousa's march, "Unchain the Dogs of War" from "The Bride Elect," was switched through the Theatrophone to the White House in Washington, where Mrs. McKinley and a party of friends enjoyed it immensely. Mr. F. N. Hawley engineered the thing, and Messrs. Webb, Brewster and Dowd carried out the arrangements perfectly. The performance attracted considerable attention on the part of the city newspapers.