189 
the Pivots of Chronometers . 
suit of his long experience, and the following extract is 
taken from his interesting answer 
To Mr. Walker . 
London , 1 3th October , 181CL 
“Dear sir, — It is, I believe, upwards of ten years 
since you first favoured me with some of your purified 
oil, which I have ever since constantly applied to my 
chronometers ; and on their return from a long voyage I 
have always found yotir oil in good condition, much bet- 
ter indeed than any which I had before been able to ob- 
tain ; nor has the superior quality of yours been confined 
to my own observation. 
“The late Mr. John Brockbank was complaining to 
me, some years ago, of the bad state in which he found 
the oil in his chronometers on their return from India, 
many of which had failed in consequence, although the 
oil he used was the best he could obtain. I then men- 
tioned the success which had attended yours, and at his 
request furnished him with a small quantity, which he 
applied to his chronometers, and afterwards very grate- 
fully acknowledged the advantage he had derived from 
its use ; having found, on the return of his chronometers 
from India, your oil in excellent condition, and deemed 
it far superior in quality, for such purposes, to any he had 
before been able to procure. 
“I have presented one of the last phials, which you fa- 
voured me with, to Mr. Vulliamy of Pall Mall, who pur- 
poses to give it a trial ; but I hope you will be induced, 
by what has been already ascertained, to make your dis- 
covery known. I am, &c. 
P. P. Barraud.” 
Pure oil , such as I have at different times sent to Mr . 
Barr and, may be obtained by attending to the following 
directions . 
