Electrical Review, November 19, 1904, page 832-833:
WIRELESS TELEGRAPHY ON MAIL STEAMERS.
BY EMILE GUARINI.
Since Marconi succeeded in sending messages across the Atlantic, the partisans of submarine cables have not been sparing in criticisms of wireless telegraphy--nearly all unjustified. These criticisms are merely card houses, and will collapse at the first breath. These persons have obstinately declared that it is not possible to maintain secrecy by syntonic work. The following account will show how this is now secured on the Belgian mail packets.
Syntonic operation is not the only solution of the difficult problem of secret communication without wires. The complete solution can only be secured by limiting the field of emission and reception of the waves. It may be said, in passing, that for about a year experiments looking to the last solution have given satisfactory results. By using several antennæ it has been possible to limit the electrical field, and it seems likely that the same limitation may be forced upon the magnetic field.
In fact, wireless telegraphy has been in Belgium, on the mail packets running between Ostend and Dover, England, thus demonstrating that radio-telegraphy has entered into a domain of current practice.
Tests with wireless telegraphy on the Belgium packets were commenced by Marconi in 1900. The coast station was established at La Panne, and provided with a mast forty-six metres high. The floating station was on the Princesse Clementine, which had a mast thirty metres high, twenty-six metres being the height from the transmitting coil. These two stations used a transmitter system consisting of an oscillator, one terminal of which was connected to the earth, and the other to an antenna. The tests were continued until October, 1901, and resulted satisfactorily. At each voyage the Princesse Clementine remained in communication with La Panne from the Ostend quay to the Dover pier. Storms, but not atmospheric electricity, exerted an unfavorable influence on the apparatus.
The Marconi system was then adopted by the Belgian government and installations were commenced in June, 1902. Communication by rail was very difficult to La Panne, and to ensure regular service the coast station was transferred to Nieuport Bains, the government owning land in that locality on which the station was erected. The city of Ostend was not chosen for lack of a suitable site. The lighthouse might have been used as a station, but the city formed an obstacle which could not be neglected.
The new station was, therefore, established at Nieuport Bains, at the side of the signal station, near the west stockade. The building is of brick, to which is carried the terminal of the antenna. The mast, just as at La Panne, was erected in the immediate neighborhood. The station has telegraph communication with the interior of the country by ordinary methods. Then, in order to send a signal to sea, it is sent to the station by wire, and then retransmitted wirelessly. On the other hand, if a signal comes from a vessel it is received wirelessly, and transmitted by wire.
During the day, from 10 A. M. to 8 P. M., two government employés are on duty, thus ensuring communication with the steamers leaving Ostend at 10.37 A. M. and at 3 P. M. and with those leaving Dover at 12 o'clock noon, and at 4 P. M. The latter reaches Ostend at about 8 P. M.
Service during the night is maintained by an employé of the wireless telegraph company. He is on duty from 11 P. M. to 3 A. M., and establishes communication with the vessels leaving Ostend at 10.58 P. M., and Dover at 11 P. M. During each night voyage each of the vessels sends an average of three telegrams. During the day trips each vessel receives one telegram.
In general, the telegrams sent from the vessel first indicate the number of passengers and postal sacks, the direction and force of the wind, the condition of the sea and sky, the time of passing the lightship, and the number of revolutions of the propeller. Telegrams received on board are intended to ensure the satisfactory operation of the system. They consist of two lines of text from a book.
The following is the order of transmission for the vessels: first, the signal of a message, a number, then the number of words, the nature of the telegram (whether a service telegram, private or government), the name of the boat, and then the text, which might be as follows: "left Dover with full head of steam at 11.03 P. M. thirty-two passengers; 270 postal sacks; cloudy; wind W. S. W.; heavy swell"; signature. If the telegram is sent during the voyage, the text would be about as follows: "passed Ruytingeu (the lightship) at 12.42 A. M., with 4,732 revolutions; all is well; the wind freshening; arrive probably at 2.50 A. M."; signature. The manipulation on the steamers is made by the commander and his officers, the employés of the telegraph company putting them in charge at that time. The stations on the steamers are syntonized--that is to say, they do not receive outside messages, and their messages do not interfere with other stations of Marconi apparatus having a different pitch. This syntonizing is required by the contract between the government and the company. With the ordinary system the Princesse Clementine and station at La Panne receive signals from all the English war vessels, and all the line stations from the other side of the strait--Dover, Trinton and North Foreland--receive them from La Paine and the Princesse Clementine. The apparatus on all the mail steamers and at the Nieuport station is identical.
The transmitting station consists of a storage battery of eight cells which supply the Ruhmkorff coil with eight amperes at sixteen volts, equivalent to 160 watts. The coil transforms the current to 40,000 volts. The storage battery is charged by the dynamo which lights the station. The antenna consists of three wires soldered together at the extremities. The total length of wire is 180 feet. The height varies on the packets from fifteen metres to twenty-seven metres, according to the height of mast.
The receiving apparatus consists of a receiver complete relay, decoherer, coherer, jigger, box of batteries, next a Morse register and a signal bell. Each station is provided also with reserve apparatus, a storage battery, a coil complete, three Leyden jars, a receiver complete, and twelve batteries.
Until recently, the installation was reserved exclusively for the government service. One exception was made, on the packet which followed the regattas the service was public, the charge being one-half franc for fifteen words.
As has been said, communication was constant between Ostend and Dover and vice versa. It is said that neither wind, rain, snow, cold nor heat exerts any influence. Four or five messages are exchanged during each voyage. But as the communication is not made at any fixed hour, the station must always be ready for receiving from the departure until the arrival. When there are no telegrams to send, conventional calls and answers are made so as to assure that communication is not interrupted. The signals of the packets and of Nieuport only are received.
All the packets receive the signals sent to any one, but as each has its call letters, only the one interested answers. Signals are exchanged best during damp moonlight nights.
Since being established on the Belgian packets, the wireless telegraphic system has rendered some important services. One may be cited.
One day the packet encountered a Norwegian bark with a broken rudder and a leaking hull. A tug was despatched immediately from Ostend when the condition of the bark was reported.
During the Dover-Ostend regatta, a packet is put at the disposition of the guests and the jury. It serves at the same time to mark the finishing point and can not for this reason reach land before the passage of the last contestant. Before wireless telegraphy was employed, three hours passed before the results could be telegraphed to the papers. Now they are sent as they are made.
The author has been present during the sending of the despatches at regattas and it was noticed that with the ordinary system, that is to say without condensers, the transmission was much more rapid than when they were used. In the latter case the transmission was excessively slow. Further, one could hear and interpret the despatches even in the cabins. Moreover, it will be easy to obviate this inconvenience by suitably muffling the telegraphic cabin.
In case of dense fogs the packets ask each other what route each holds and if the siren can be heard. This condition occurred in the night of February 9-10, 1903, between the Leopold II and the Marie Henriette.
During the same night the Leopold II was grounded. By means of wireless telegraphy a tug was secured immediately and by disembarking the mail and passengers the latter did not even miss their train.
An incident of the same kind occurred two months later. A tug was called by wireless telegraphy to aid the Princess Henriette, which had broken a propeller.
When the light-buoy, marking the Ostend channel, accidentally went out the pilot warned the packet, which then took care not to miss the route. This happened in January, 1903. Should a packet be delayed the railway official is warned and he then takes the necessary measures. One more fact before closing, which shows that the police may find the service of assistance. A robbery occurred in Brussels and it being thought that the thief might have taken the packet, the vessel was signaled by wireless telegraphy, and the commander made the search requested.