218 Admiralli/ Clironomctikal AjJ'airs. 



scientific purpose, (for I would protect it from Humean fangs,) 

 and perhaps to none better^ than restoring to^ its -pristine excel- 

 lence the Nautical Almanac, or Astronomical Ephemeris. 



But, to return from this digression; by reference to the pre- 

 ceding pages it will be seen what are the requisites of a good 

 chronometer, and what are the means which, i/" adopted, seem 

 most likely to enable us to select the good, and reject the bad. 

 Having also shewn that a chronometer may be good in one re- 

 spect, yet bad in another, it remains that we should see how far 

 the mode of trial sanctioned by the Admiralty, and carried 

 on under its authority, accords with that which we have con- 

 sidered indispensable. 



The Admiralty places its chronometer horizontal, and daily 

 comparisons with a good clock are enforced : our plan also re- 

 quires this. The Admiralty exposes its chronometers to alte- 

 rations of temperature, such as are to be met with in a com- 

 mon sitting-room * ; our plan does the same. We try our chro- 

 nometer vertically, and in different directions of its axis ; the 

 Admiralty does no such thing. We try the effect of motion 

 upon our chronometer ; the Admiralty does no such thing. 

 We expose ours to extremes of cold; the Admiralty does no 

 such thing. We try ours in extremes of heat ; the Admiralty 

 does no such thing. We compare the various results produced 

 by these alterations of circumstances upon our chronometer, 

 because we wish to take not any thing for granted ; the Admi- 

 ralty having ascertained one fact, and that, perhaps, of the least 

 importance, takes evert/ thing else for granted. We take all 

 this trouble, that we may get a good chronometer; the Admi- 

 ralty saves all this trouble, and will probably get a bad one. 



On comparison, therefore, of the two modes, knowing, as I 

 do, and shewing, as I trust I have done, that the various trials 

 I have advised are necessary, the only inference I can draw is, 

 that the chronometrical arrangements at present conducted 

 under the sanction, and by the authority, of the Lords Com- 

 missioners of the Admiralty, are inadequate to the pur- 

 poses FOR AVHICH they WERE DESIGNED. 



J. South. 

 Blackman-street, March 22, 1822- 



* The printed papers inform us, that the chronometers have been ex- 

 posed to differences of temperature equal to 8" of Fahrenheit. 



