One of these weapons was perfect, the other minus her fore compartment, this having been knocked off by the torpedo colliding with some hard object. No explosion was heard or seen by the Turks. This was the second time that the fish torpedo had been employed on actual service, and, as in the previous instance, failed. The guard boats and barrier of the Turks seem to have been of little avail. 8TH AFFAIR. _The Final Attack._--The eighth and last attempt was made on the night of the 25th-26th of January, 1878. This was originally intended to be an attack on the Turkish fleet at Batoum, but on entering that harbour the two Russian torpedo boats, the _Tchesme_, Lieutenant Zatzarennyi, and the _Sinope_, Lieutenant Stchelinski, were met by a Turkish revenue steamer, against which the boats discharged their Whitehead torpedoes, resulting in her complete destruction, at the same time arousing the squadron, and causing the boats to beat a retreat. Though the vessel destroyed was not a frigate, yet the expedition was successful in so far as proving that it is possible to project Whitehead fish torpedoes from boats at a distance of 70 to 90 yards from an enemy's ship, on a dark night, and strike her with them. This concludes the whole of the offensive torpedo operations that were carried out during the war, of which two out of eight attempts were successful, which is without doubt a fair percentage. There seems every probability that the present struggle between Chili and Peru, in the Pacific, will afford torpedoists further experience of the various offensive torpedoes, when subjected to the test of active service. FOOTNOTES: [Footnote Q: See page 185.] [Footnote R: A Turkish port, situated on the east coast of the Black Sea, capable of holding several large ships when anchored head and stern, but otherwise only a few.] [Footnote S: A town situated on the south bank of the Danube, about eight miles from Brailoff.] [Footnote T: One of the principal mouths of the Danube.] [Footnote U: A place taken from the Russians in the early part of the war, situated on the east coast of the Black Sea.] CHAPTER VIII. ON EXPLOSIVES. EXPLOSION may be defined as the sudden or extremely rapid conversion of a solid or liquid body of small bulk into gas or vapour, occupying very many times the volume of the original substance, and which in addition is highly expanded by the heat generated during the action. This sudden or very rapid expansion of volume is attended by an exhibition of force which is more or less violent, according to the constitution of the original body and the circumstances of the explosion. Any substance capable of undergoing such a change on the application of heat or other disturbing cause is called an "explosive." _Explosive Force._--Explosive _force_ is _directly_ proportional to the heat of combustion and the volume of gas, and _inversely_ to the specific heat of the mixed products.