Fog-Signalling by Explosives
1875; Taylor & Francis; Volume: 19; Issue: 82 Linguagem: Inglês
10.1080/03071847509415768
ISSN0035-9289
Autores Tópico(s)Advanced Malware Detection Techniques
Resumo0s Fridayweck Admiral Collinson read a paper in this thcatrc mliieh mts listcncdto -i-iith great interest, on thc gcncral subject of ''Fog-Signals."He described fully certain cspcrimcnts which ~c r c carricd on in 1873 at the South Foreland by thc Trinity Board, undcr the mtchful care of Professor Tpdall.Hc explained that under some conditions of the atmosphcrc the sounds produced by horns, whistles, and notablr by the siren, penetrated the distancc morc sncccssfully than thosc of guns; while, under othcr conditions, tho dull thud of an explosion made itsclf heard when all othcr sounds m r c stilled.Tho note of thc most poTerful instrumcntpt tricd-thc sixen-resembles harsh, prolonged scream, and thus is less likely to bc annullcd by ~1 puff of +nd or a local disturbance than thc \-cry bricf sound of a gun ; on the othcr hand, the lattcr sound, \Then hcard, is less likely to be mistaken or ovcrlookcd, for, as most of thosc present ham probably espcricneed, thc report of a piece provokes instant attention.The Elder Brcthrcn of tho Trinity Board thercforc conccivcd the idcn of differentiating thc signals, by placing sircns on board light-sGips hnd guns on shore stations, so that tho bcfoggcd marincr might be &lc to tcll npprosimatcly what part of tho coast was near him.Admiral Collinson csplained also thnt on diffcrcnt d a ~s the atmosphcrc varied pcatly, so much so that sounds audible up to 15 milcs one day were lost at 3 milcs on another.This irregularity affected all sounds in about equal degccs.
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