[ 364 ] 
LXXVI. Concessions to Mr. Ivory. In a Lelter to the Editor. 
Sir, MusT apologize to your readers for recalling their at- 
tention, after an interval of four or five months, to a question 
which they perhaps were rather pleased than sorry to think not 
likely to be revived. But I have some concessions to make to 
Mr. Ivory, and the computations of such a mathematician, as he 
is, are not to be hastily or lightly examined, even by a person as 
completely at his leisure, as the Coronation and the summer 
amusements of a watering place can have left him. 
I have no pretensions to *‘ wii,”’ and I am not fond of ** banter- 
ing”’ or “sneering ;”’ but I do claim the merit of preserving ny 
temper unruffled, even when I am attacked, without provocation, 
on my own ground: when my assertions are not only denied, 
but even my “ veracity” is called in question. 
I am therefore most ready to admit, in the present instance, 
that the slight difference of the elements of the cohesive proper- 
ties of mercury, employed by the English and French philoso- 
phers, appears to make a greater difference in some of the re- 
sults of the calculation, than I was at all aware, before I read 
Mr. Ivory’s last paper. I will alsoadmit that Mr. Ivory has con- 
vineed me, by means of the series, that his formule are more ac- 
curate than | had some reason to suppose : for it was only from 
such a comparison, that I could form any opinion, how far the 
quantities, which he has professedly neglected, were or were not 
wholly inconsiderable. And this is still my principal objection 
to his “ refinements.” 
On the other hand, the series, “ clumsy” as it certainly is, 
does afford in all cases a mode of es/imating the utmost possible 
magnitude of the terms omitted: and if we may trust Mr. Ivory’s 
own latest calculations, it agrees, even in the last place of deci- 
mals employed, with the formulas which he supposes to be suffi- 
ciently correct. When however he “ took the series into his 
hands,” I really was in hopes that he would have employed his 
undoubted talents in improving it, or in facilitating its applica- 
tion: and that the conclusions, which he considers as probably 
deducible from it, would at least have been converted into cer- 
tainties. The labour of a few days would be sufficient to com- 
pute coefficients enough to remove much of the difficulty ; and 
when once computed, they would last for ever. But it is said 
that great mathematicians have often been bad computers. 
I feel no reluctance in admitting that the table of 1809 is im- 
perfect, not only in the instance which Mr, Ivory has re-com~ 
puted very accurately, by the help of the clumsy series (p. 425) ; 
but perhaps in many others. It is however remarkable enough, 
that this table, with all its imperfections, is, in every instance, 
nearer 
