Wireless telegraphy had come into use since the last naval war, and a fleet could now try to overhear the aerial messages of an enemy. In the Russian fleet the order had been given that no wireless messages were to be sent. In other words, the operators were to keep silence, and listen by watching their apparatus. In the morning of the 26th they thought they detected messages passing. In the evening these were more frequent--"short messages of a word or two" was the interpretation that the experts in the signal cabins put upon the unintelligible flickerings of the indicator, and they suggested that they were mere negative code-signals from the Japanese scouts to their main fleet, repeating an indication that they were on the alert, and had seen nothing. This was mere guesswork, however, and Politovsky's diary of the voyage[28] shows that near the Cape, at Madagascar, and out in the midst of the Indian Ocean, Rojdestvensky's wireless operators had thought that they detected Japanese aerial signalling, simply because the receivers gave indications they could not understand. Possibly these were merely the effect of electric storms on the apparatus. [28] "From Libau to Tsu-shima." By the late Eugene S. Politovsky. Translated by Major F. R. Godvey, R.M.L.I. 1906. Once or twice, on 26 May, they thought they could read fragments of sentences, such as--"Last night--nothing--eleven lights--not in line." The short messages in the evening came at fixed times. This showed that prearranged signalling was really going on. It gave the impression that perhaps the fleet was being watched by unseen enemies. As the sun went down the ships closed up, and half the officers were detailed for duty at the guns during the hours of darkness. The rest lay down fully dressed, ready to turn out at a moment's notice. Many slept on the decks. No lights were shown. Semenoff's description of that night of anxious expectation is worth quoting. He was on board the flagship, the "Suvaroff":--