575 
of Edinburgh, Session 1874 - 75 . 
several points of fact and of doctrine which he regards as deducible 
from my writings; writings which he has misinterpreted, doubtless 
from an incomplete knowledge of the French language. In pre- 
paring the following note I am aware that I am exposed to a 
danger of the same kind, and therefore count upon Mr Sang’s 
indulgence, as he may assuredly count upon mine. 
I. Mr Edward Sang does not admit that Ylacq’s Table corrected 
by help of my errata can supply the place of the new tables which 
he proposes to print. He argues that Ylacq’s Tables can only be 
had at a great price, and that the 4th volume of the “Annales de 
l'Observatoire de Paris,” is not always easily obtainable; and also 
that there is not a complete agreement among the different copies 
of Ylacq’s work. In support of this thesis he quotes the following 
phrase, which should be found on the 64th page of Taylor’s Tables: — 
“ In about 100 copies; in about 200 copies; doubtful whether a few 
copies are erroneous or not; in about half the impression; only in one 
copy; and so on.” 
I have a copy of Taylor’s Tables, published in 1792 at London, 
under the care of Maskelyne. Therein I find at page 64 an errata 
with this notice, very different from the preceding: — “Errata of 
the Logarithmic Tables which affect only part of the impressions 
of the sheet, and have been corrected by the printer since the 
impression, except any may have escaped correction through 
inadvertence.” 
Have there been several editions of Taylor’s Tables? I know 
nothing of it. But the preface to the edition just mentioned shows 
that the publication was made for the first time under Maskelyne’s 
care. Any way the two quotations seem to me to apply exclusively 
to Taylor’s work, and to have no reference to that of Ylacq. 
The errata which I have given in vol. 4 of the “ Annales de 
l’Observatoire,” refer to the Arithmetica Logarithmica par Adrian 
Ylacq, Gfoudanum, Gfoudae 1628, Petrus Bammasenius, and not to 
any spurious copies. 
As to the hypothesis of the types drawn out in the working of 
the “inking dabber,” and misplaced by the pressman; I cannot 
imagine how it could be, because it supposes the complete neglect 
of the most elementary and usual verifications; an omission much 
