96 Catalogue of Moon-Culminating Stars. [Feb. 



which are sure to be made in Europe, would enable us to fix the longi- 

 tude of places here relative to the principal observatories in Europe. 



With the view of holding out every possible inducement to gentle- 

 men to make these observations, I have inserted the apparent right ascen- 

 sion of the stars, although so far as this method of determining the 

 longitude is concerned, the mean places would have answered equally 

 well; and if inserted, would have saved me much trouble. But as gen- 

 tlemen in India, for whose use this catalogue is intended, may not have 

 accurate time-pieces, nor sufficient leisure to determine the errors of 

 them, or the deviation of their instruments from the meridian, I have 

 inserted a few stars which it appeared to me could be observed 

 without in any manner trenching upon the time necessary for the other 

 observations, and which if observed would enable us to determine the error 

 of the time-piece and the deviation of the instrument from the meridian 

 at the time of making these observations, and thus to render the kind 

 of watch employed but a matter of secondary consideration. 



The certainty with which the longitude can be deduced by this me- 

 thod appears to me so great, as to induce the conviction that many 

 gentlemen would gladly make an extensive series of such observations, 

 if they saw the chance of corresponding observations being made to 

 confer a value upon their labours : and, as they may rest assured that 

 those observations will be cheerfully made by Mr. Taylor of the Madras 

 observatory, they will be sure of having at least one point of reference 

 besides those which their own labours will create. With the view then 

 of affording all the aid which circumstances at present place at my dis- 

 posal, I send you the accompanying catalogue, and will continue to pre- 

 pare others for circulation in succession through the same channel, till 

 experience shall have convinced me of the propriety of discontinuing 

 them. 



I have but one more remark to make — and that is, that it appears to 

 me to be most desirable that gentlemen should transmit their observations 

 as they are made, which you could arrange in the form of a table, and 

 publish for general information. In this manner all parties would be ena- 

 bled to compare their own observations with those of others, and assign 

 a cause for any anomaly which these comparisons should point out. To 

 make these observations of permanent value, I shall, I trust, be excused 

 for stating, that it appears to me to be very desirable that the spot 

 whereon they are made should be more accurately defined than similar 

 observations made in other places have hitherto been : — that, in short, 

 an exact measurement of the distance of the observatory from some re- 

 markable and natural objects should be given, so that the position of 

 these, and of the observatory, should be permanently preserved. 



