the Pivots of Chronometers, 373 



« To Mr. Walker. 



" London, 13th October, 1810. 



" Dear sir, — Tt is, I believe, upwards of ten years since 

 you fiist favoured me with some of your purified oil, which 

 / have ever since constantly applied to my chronometers; 

 and on their return from a long voyage I have always 

 found your oil in good condition, much better indeed than 

 any which I had before been able to obtain; nor has the 

 superior quality of yours been confined to my own obser- 

 vation. 



" The late Mr. John Brockbank was complaining to me, 

 some years ago, of the bad stale 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 mentioned the suc- 

 cess which had attended yours, and at his request furnished 

 him with a small quantity, which he applied to his chrono- 

 meters, and afterwards very gratefully 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 bad before been able to procure. 



i( 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 discovery 

 known. 



" I am, * * * . 



" P. P. Barraud." 



Pure oil, such as I have at different times sent to Mr. 

 Barraudy may be obtained by attending to the following di- 

 rections. 



Put a quantity of the best olive oil into a phial with two 

 or three times as much water, so that the phial may be 

 about half full. Shake the phial briskly for a little time, 

 turn the cork downwards, and let most part of the water 

 flow out between the side of the cork and the neck of the 

 phial. Thus the oil must be washed five or six times. — 

 After the last quantity of water has been drawn off, what 

 remains is a mixture of water, oil, and mucilage. To se- 

 parate these from each other, put the phial into hot water . 

 for three or four minutes, and most part of the water will 

 fall to the bottom, which mtict be drawn ofl* as before* 



The oil must then be poured into a smaller phial, which, 

 2 A 3 being 



