The following are transcribed from a news weekly published in New Zealand, Te Aroha News, Rōrahi II, Putanga 72, 18 Whiringa-ā-nuku 1884, Page 3 [click on the left image and single click again to get an enlarged view]:
London October 13  - "The French fleet have been prevented from entering Tamsui on account of torpedos having laid across the entrance to the harbour, and in consequence of this, they have blockade the port."
Hong Kong October 10 - "Later intelligence from Formosa shows that the report of the occupation of Tamsui by Admiral Lespes is incorrect. The town is still in the possession of the Chinese troops, and the French bombardment is continued daily. The local forces are strongly entrenched in the neighbourhood of Tamsui, and all efforts to dislodge them have as yet proved unavailing."
Hongkong October 14 - "Intelligence has been received here that on the 8th inst. a considerable French force landed at Tamsui, Formosa. A severe engagement with the Chinese ensued, in which the French suffered heavy loss, and were compelled to withdraw and returned to their ships in port."
"A London telegram gives the following version of the engagement: -- 600 French troops at Tamsui were led into a ambuscade, when 20 of their number were killed and beheaded. The remainder managed to return to their ships in safety."
News actually traveled fast at that time because wired telegraphs were the main communication tool in the late 1800s. Taiwan was no stranger to the then novel tele-communications scene. In 1877, a 95-km telegraph cable system, the very first in China, was built in Taiwan [between Tainan and 鳳山Feng-shan]. In 1887, the first undersea cable was laid between Taiwan and Foochow. And the 電報學堂telegraph academy in Taipei began its first class in 1888.
Battles in the Sino-French War were also greatly facilitated by cable communications especially for the Chinese. Starting in 1881, the 3,075-km land line connecting Tientsin and Shanghai [津滬電報線] was established. And between 1883-4, a network linking 京津, 長江, 廣州, and 龍州 areas was also constructed. This completed a nationwide communications system. With it, instead of relying on the "pony express", the to-and-fro military orders could be dispatched instantaneously. This proved pivotal in several successful campaigns against the French in Tonkin. Before the cables, the Chinese were fighting blindly especially in the beginning when the intelligence reports to the highest command in Beijing and the orders back to the field commanders took more than 50 days.
Prior to this Chinese cable network, in 1868, the British had laid undersea cables from the Mediterranean, through the Indian Ocean to Hongkong. And starting in 1869 the Scandinavians (actually the Danish) took the northern route by stringing lines through Siberia to China (Shanghai) and Japan. All news reports, commercial transactions, and wired transfers were based on these cable routes.
Adm Courbet had used the French Consulate in Hongkong as his communication center, no doubt by tagging onto the British lines. Pictured below is the British Eastern Extension Telegraph Company's Hongkong office, ca 1873: