418  Replyto Mr. Hawes’ Attack upon the received [June 1, 
be printed from a copy corrected by the 
author, and carefully revised by —— L. 
Gwynne, A.M. master of the Royal 
Mathematical School, Christ Church, 
London, &c. &c. and, observing that 
a very material error still remains uncors 
rected, I beg, through the medium of 
your very useful publication, to point it 
out, for the benefit of such persons as 
may use the tables in the above work. 
The error [ allude to isin the applica- 
tion of the second part of the equation to 
equal altitudes, (in Table II.) as ex- 
plained by an example in page &1, which 
the author prefaces thus, “ Another ex- 
ample will make every thing relative to 
these tables perfectly plain to the 
meanest capacity.” 
In this example the latitude is 33°°56' 
south, and the first part of the equation 
10”:64 which is subtractive, because, the 
latitude being south, the sign is changed 
from + to—. But we are told that the 
second part of the equation 1-25, is sub- 
tractive likewise, naturally leading one, 
not of the meanest capacity, to suppose 
that the signs in Table IIL. are to be 
changed when the latitude is south, 
which is contrary to the construction of 
the table, and will certainly produce an 
erroneous conclusion in the calculation ; 
for in the present instance the whole equa- 
tion is said to be — 11"'89, instead of 
which it ought to be — 9"-39, being the 
difference instead of the sum of the two 
parts of the equation, and subtractive 
because the greater part is so. M. 
a 
To the Editor of the Monthly Magazine. 
SIR, 
‘HAVE read in your last Number a 
communication entitled “ Objections 
to Doctrines adopted by Mr. Baily and 
eather Writers, on the Probabilities of 
Life,” by Nathaniel Hawes, on which I 
beg leave to send you a few comments. 
Mr. Hawes first briefly mentions the 
manner in which the probability of life 
has been expressed by Halley, De 
Moivre, Simpson, Dodson, Price, Mor- 
gan, and Baily ; and then states, that the 
purport of his letter is ‘‘ to represent the 
fallacy of such a doctrine.” This cer- 
tainly is a very modest beginning, and T 
assure you that, when T had proceeded 
only thus far, I formed no very elevated 
opinion of the ability of your corre- 
spondent; for, though I by no means 
think it proper that we should place an 
implicit confidence in names, particularly 
when we may, by the exercise of our 
$0:0000 © 
own reason, ascertain the truch or false. 
hood of whatever has been delivered 
concerning the subject of our enquiry ; 
yet when men, pre-eminently distin~ 
guished for their abilities, and for their 
arduous enquiries after truth, have suc- 
cessively maintained a doctrine by the 
force of reason and argument alone; I 
think it must be confessed, that sud- 
denly to renounce such doctrine, and to 
pronounce it fallacious, argues a degree 
of self-confidence which is more ge- 
nerally fuund to accompany vanity and 
ignorance, than truth and knowledge. 
Mr. Hawes next vives a very obscure 
and inelegant definition of what he 
“* takes to be” a fraction; he then pro- 
ceeds thus: “ By consulting Nature in 
preference to. my own imagination, or to 
any received doctrine, I find the proba- 
bility that a person, whese age is twenty, 
shall attain to the age of fifty, or live 
thirty years, is, according to the obser- 
vations of M. De Parcieux, as given 
in Mr. Baily’s third table, equal to 
25°6689 
30:0000 
did not your correspondent acquaint his 
readers with the method by which he 
found the probability that a person, 
aged twenty, should attain to fifty, was 
25°6639 
years.” But why, Mr. Editor, 
Not one word however has he 
said of the modus operandi. No, but he 
says that he has consulted Nature: true, 
I know he says that he has consulted 
Nature; but may not his reader be at 
liberty to doubt the truth of this asser- 
tion? For does it not seem strange that 
Nature should have thrown her whole 
blaze of light upon Mr, Hawes, and have 
afforded only a few occasional rays to 
Newton, Halley, and De Moivre; rays 
too, which it should now seem, only 
served to bewilder and deceive them? Is 
it not extraordinary that Nature should 
have been so munificent of her favours 
in, most probably, her first interview with 
your correspondent, and that she should 
have been so coy in her manners, so re- 
served in her appearance, and so nig 
gardly of her gifts, to those great men, 
who spent their whole lives in her so- 
ciety? Surely, therefore, Mr. Editor, 
your readers may be at liberty to doubt 
this consultation with Nature, and to 
rank it in the class of those experiences, 
as they are called, which are not un- 
frequent among the members of a certain 
religious persuasion, but which are some- 
4 times, 
