The same tubes used for parcel delivery would also be used for a district messenger service. With numerous public stations in convenient locations, all the advantages of the European system would be realized in the quick despatch of letters and telegrams. Every one knows how much time is consumed by district messenger-boys in the delivery of messages, especially when they have to go long distances, and no argument is required to show that this time would be very much reduced by the use of pneumatic tubes, besides prompt delivery would be made much more certain. The tubes of this system were to be six or eight inches in diameter, with a few small tubes in localities where the message service is very heavy. Without going more into detail, such were in brief the plans of the promoters of this new company; but before launching such an enterprise, involving a large amount of capital, there were many engineering and mechanical problems to be solved. It was not simply a question of obtaining tubes and laying them in the streets, but ways and means for operating them must be devised. Up to this time only small tubes had been used for the transmission of telegrams, messages, cash, and other light objects. Now it was proposed to transmit heavy and bulky material. There was no experience for a guide. =The Clay-Lieb Patents.=—The Pneumatic Transit Company at this time turned to the Electro-Pneumatic Transit Company, of New Jersey, a national company that had been in existence since 1886, and which claimed to own valuable patents, for the ways and means to carry out its new enterprise. The patents were those of Henry Clay and Charles A. Lieb, and the rights to use them in the State of Pennsylvania were procured by the Pneumatic Transit Company, under a contract entered into between the two companies. The patents claimed to cover a practical working system by which a large number of stations could be connected to a system of main and branch tubes, with electrically-operated switches at the junctions of the branches with the main lines. Any person who gives the subject a little thought will at once see the advantages of such a system if it could be made to operate. Up to the present time only single- or double-line tubes have been used, without branches. In the European systems, frequently several stations are located along a line, but the carriers must stop at each station, be examined, and if they are destined for another station, they must be redespatched. The cash systems used in many of our large stores have independent tubes running from the central cashier’s desk to each station about the store. It is plain to be seen that, if several of these stations could be connected by branches to a main tube, a large amount of tubing would be saved—a most desirable result. The advantages of such a system would be still greater for long lines of tube laid under the pavements, extending to stations located in different parts of a large city.