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POPULAR SCIENCE REVIEW. 
were framed and enquire into the value they were found to 
possess'; but, before doing so, let us describe the mechanical 
arrangements adopted for signalling them, and illustrate by 
actual examples from official sources the details of the modus 
operandi , of which an outline only is presented above. 
The necessary apparatus consists of a mast, .of any convenient 
height (thirty or forty feet) two yards from four to six feet in 
length with the necessary ship’s tackle, a cone, a drum and four 
signal lanterns. The cone and drum are wooden frames of 
those shapes covered with canvas and each about three feet 
high ; any sort of lanterns may be used, but they must be of 
good size and show the same colour ; what that colour be is not 
of great importance but red is to be preferred as the colour 
which is most conspicuous. 
When hoisted, the cone appears as a dark triangle, and the 
drum as a dark square, and the import of the various signals 
is as follows : — 
The cone with the point upwards, shows that a gale is 
'probable ; at first from the northward . This is termed for 
brevity “North Cone,” fig. 1. 
The cone with the point downwards shows that a gale is pro- 
bable ; at first from the southiuard . “ South Cone,” fig. 2. 
The drum alone, shows that stormy winds may be expected 
from more than one quarter, fig 3. 
The cone and drum together give warning of dangerous winds, 
the probable first direction being indicated by the position of 
the cone and its apex : cone over drum and point of cone upper- 
most for northerly wind (fig. 4) : cone below drum and point 
downwards for southerly wind (fig. 5). 
When these signals were, in consequence of telegrams from 
London, made at the several stations warned, they were kept up 
till the dusk of that day only, and in the official instructions 
issued it was stated “ These cautionary signals advert to winds 
during some part of the next night and two or three days ; 
therefore due vigilance should prevail (until the weather is 
again settled) without deferring departures or any operations 
unnecessarily .” 
In night signalling, only one of the two signals was used ; 
drum or cone, but not both. This was for the sake of simplicity 
and saving of trouble. 
Let us now revert to the procedure at the Central Office in 
London. When the system was first instituted the British Isles 
were divided into 6 districts, viz.: — 
1. “Scotland.” 
2. “ Ireland,” around the coast. 
3. “ West Central ” (from the Severn to the Solway). 
