Page:Popular Science Monthly Volume 88.djvu/46

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HE drawback to window demonstration of any character is the inability of the demonstrator to get his "message across." He can clearly point out the talking points of the article under demonstration, but he can talk about it through the medium of lettered cards only. It is obvious that this method is very unsatisfactory. To overcome the objection and bring the demonstrator nearer his audience, an electric company has developed a loud speaking telephone equipment.

The equipment consists of a special transmitter and a pair of loud speaking receivers and horns. The operation of the system is simple. The demonstrator connects the horns and receivers oh both sides of his window, just high enough to be outside the reach of mischievous youngsters. The transmitter is placed inside the window and is wired with the battery of six dry cells in series.

As the demonstrator wishes to bring out each point, he simply speaks into the transmitter and his voice is magnified by the receivers and horns and carried to the audience outside. The equipment not only brings the demonstrator and his audience into more intimate contact, but serves as an auxiliary attraction to the display itself. It has proven a success wherever used.

WO large steamships, the Finland and the Kroonland, will be changed from coal to oil burners. By this, change it is expected that $9,000 will be saved on fuel and $3,500 in wages on each trip. In addition, by the large space now occupied, coal may be used for the storage of freight. A total saving of $37,500 is expected on each trip.