Guglielmo Marconi's skepticism about the practicality of the Collins wireless telephone, which used conduction rather than radio waves, turned out to be correct, as the technology was never improved beyond the range of a few kilometers at best.
Leslie's Weekly, February 6, 1902, page 129:
Collins conduction wireless telephone experiments
Telephoning  without  Wires:  Is  It  Practicable?

THE RECENT experiments of Professor Frederick Collins with the wireless telephone at Narberth, Penn., a suburb of Philadelphia, have attracted much attention. Signor A. Marconi, inventor of the wireless telegraphy, commenting on Professor Collins's experiments to a representative of LESLIE'S WEEKLY, said:
    "The system used by Professor Collins is good only for short distances. Under ordinary circumstances the limit would be about a mile. I have tried the same experiments myself, and for long distances the system is not successful."
    Appended is a brief description of the apparatus and methods used by Professor Collins, which is contributed to LESLIE'S WEEKLY:
    Out in the suburbs of Philadelphia, Penn., several men have been working for the last year with an apparatus which at a distance looks like a camera mounted on an ordinary tripod. As a matter of fact, it is a telephone which can be inclosed in a case like a camera, carried from place to place and used without wires. So much has been heard about wireless telegraphy recently that the experiments which have been conducted by Professor Frederick Collins are almost unknown, yet he has succeeded in receiving and sending messages at the distance of a mile by his invention. When Professor Collins began his work in the little suburban town of Narberth, Penn., the residents thought that a party of photographers and surveyors were at work as they saw the men with tripods on their shoulders going from place to place. Later, when they found that the parties were talking to each other across fields and valleys and through woodland they looked for the familiar telephone pole and wire, or some connection between the stations, but found nothing.
    Like Marconi, Professor Collins uses only natural means of communication--the earth--although he claims the system would work as well at sea as on land, and possibly better, for his theory is that the electric current for the transmission of telephone messages can be conducted as easily as where the wireless telegraph is used, although he has made but a beginning in his experiments. While Marconi has used lofty elevations and recently has sent and received messages by means of kites connected by wires with the earth, the Narberth experiments have been conducted close to the ground, as indicated by the apparatus. If Professor Collins established stations in tree tops or at the top of towers 100 or 200 feet in height, he believes he could easily telephone without wires a much longer distance than at present, but he is working on the principle that the system, to be practical, should be as simple as possible; and the stations consist merely of the telephone batteries, wiring and tripod, which, as already stated, could be carried from point to point as easily as a camera or a grip.
    In using the wireless telephone at Narberth the receiver is connected with a Crooke's tube, induction coil and cell battery, all of which can be packed in a small leather case. The receiver and the transmitter, as will be noticed in the photographs, are similar to those used for the ordinary telephone work, as is also the case with the batteries. When communication is to be opened between one place and another, one operator goes to his position, takes the apparatus from the case, connects the battery with the instruments and the latter with two wires extending to the ground, not only to receive but to deliver messages. The other station is formed merely by taking the battery and other apparatus from the case and mounting the induction coil and transmitting instrument on a little table which screws into the top of the tripod. From the table extend two wires, one of which connects with another battery and the other with a sheet of copper about twelve inches square, which is perforated. Throwing up two or three spadefuls of earth the operator places the copper sheet with its wire connection in the ground and covers it. The line is now in readiness for operation, and actually no other work is required. As already stated, at a distance of a mile, conversation can be heard as distinctly by means of the wireless system as in the use of the ordinary telephone where wires form the entire circuit. The state of the weather and also the nature of the country affect the articulation, if it can be termed such, to a certain extent. On a rainy or misty day the sounds are not quite as distinct, although wet weather does not interrupt the communication. It is also found that the system works better across a fairly level space, like an open field, for instance, than when it is separated by woodland, a stream, or a valley. The wireless telephony meets the same difficulties as wireless telegraphy, to a certain extent, and Professor Collins, in conducting his experiments, has made a study of the Marconi system. The inventor predicts that eventually this method will take the place of the ordinary telephone circuits, and he believes that it will be especially valuable at sea, as vessels can be equipped with the apparatus and their officers engage in conversation while the craft may be several miles distant. The United States Navy Department has become interested in the matter and has decided to test the Collins apparatus on board the North Atlantic squadron.                  D. A. W.