98 
with any degree of positiveness, but are 
merely submitted, as being what the 
measurements of ‘the various spectra 
seem to indicate. 
The colour in the second column is 
merely the general appearance of the 
star as to colour when viewedin the man- 
ner already described, before the rays 
meet in a focus in the telescope; and is 
of no particular utility, otherwise than 
by reminding the reader of the general 
varieties of colour of stars. 
I have not detailed the peculiarities 
of the coloured spectra, from want of 
time, and because the detail would take 
up too much space in your valuable 
Magazine. But I have given the results, 
as nearly as I could estimate them, in 
column 3. The following seems to be 
the order of the refrangibility of the pla- 
nets ; but I have not been able to state 
any proportions, as the principal method 
employed to disperse the light of the 
stars will not disperse that of the 
planets, 
TABLE. 
Whether 
the Proper 
Planet, Colour. Refraction 
+o— 
the Mean. 
Moon ....| Bright white ..|-++ 
Venus ....} Bright white ../+]) . 2 = 
Jupiter. . ..| Greenish A 225 
! low white. . i 3 35 
Saturn ....| Dull white....J= (4 53 
Mercury ..| Reddish...... —| 55 
Mars. ....| Very Red ....|— 
Thus the moon requires the most, and 
Mars the least correction for refraction. 
T. Forster. 
’ Hartfield, East Grinstead, 
July 17, 1824. 
_ a 
For the Monthly Magazine. 
ON THE DANGERS OF OPEN BOATS. 
N open boat, notwithstanding the 
skill and dauntless intrepidity 
with which it is managed, notwithstand- 
ing the almost miraculous feats which it 
has been known-to accomplish in even 
outliving a storm when a large ship has 
gone to the bottom, and notwithstanding 
the sundry contrivances which have been 
adopted to give it security, is one of the 
most perilous situations in which a 
mariner can be exposed, as the almost 
weekly disasters recorded by the news- 
papers incontestably prove; in short, 
it would be absurb to enlarge upon, or 
to discuss this fact, which is so notorious 
and self-evident.’ 
On the Dangers of Open Boats. 
(Sept. 1, 
To preserve the lives of a most valua- 
ble set of men in their perilous efforts to 
assist a ship in distress, and the perpetual 
dangers which attend a common boat, 
has induced me to try if something under 
the influence of a sail could not be con- 
structed, so as to communicate from the 
shore, to a ship in distress, or to 
encounter a gale of wind without much, 
(if any) danger, at least not the danger 
of the common boat; and I think I have 
made a model-which will answer every 
purpose, either as a life-boat, a fishing- 
boat, (for this is often exposed to immi- 
nent. danger, as the word, Clovelly, too 
painfully brings to one’s recollection) 
or for any other general use where dan- 
ger is to be apprehended, and necessity 
requires that a boat should put to sea. 
This boat, according to my model, may 
be made to any size, for two men, or for 
eight, ten, or a dozen, rigged in any cha- 
racter calculated either for the sail or 
the oar, but chiefly the sail; it may be 
easily managed, and will work ‘itself 
without any other manual assistance 
than the rudder; it cannot remain 
upset ; or if it should be momentarily ‘so, 
no injury will arise, because it must 
instantly right again; nor yet sink 
though ten thousand waves wash over 
it ; and though it has neither cork nor air 
barrels, it may be built so light as to be 
easily launched, and will work off upon 
lee-shore much better than the common 
Beer or Deal boat in the sharpest surf, 
either without difficulty or danger to its 
crew ; and will go as near to the wind, 
make less lee-way and sail with as much 
speed as any boat that ever has been 
built ; and I. may with truth add, without 
so much as wetting the jacket of its crew, 
and affording an ample stowage accord- 
ing to its size, without being encumbered 
with any thing that will retard its course. 
It may be shaped either for celerity, for 
burthen, or for common purposes, and I 
am sure that 10/. would most amply sup- 
ply all the extra expense of a common 
boat, and every common boat can be con- 
verted into it without the least difficulty ; 
though a boat, to be built with an eye to 
this improvement, if such on inspection 
and consideration it should turn out 
to be, would be preferable; still the 
common boat could be easily converted 
to it; but, as I have said before, not so 
well as one that was originally intended 
for this purpose. 
Tam. no sailor, and not much of 3 
mechanic, nor do'I live in a sea-port, or 
know whether any boat answering. the 
deseription here given has: ever been 
: offered 
