Trigonometrical Survey. 66y 



time ; and Mr. Dutton's house in Fleet-street is about 2 s west 

 of St. Paul's ; * wherefore, its longitude west of Greenwich is 

 25 s : consequently, i6 m 3 S ,55 -f 2 5 s == 1 ^ m z&>55> 1S tne dif- 

 ference of longitude between Greenwich and Plymouth, as 

 shewn by the timekeepers. 



Now the meridian of Mr. Mudge's transit-room, at Plymouth, 

 passed only 35 feet to the eastward of the centre of St. Andrew's 

 Tower, his northern meridian mark being on the church itself; 

 therefore, the longitude of the church and transit-room may be 

 considered the same. From the survey, we find it to be 

 i6 m 30 s , 1 ; and, from Count Bruhl's determination, making a 

 just allowance for the difference of longitude between the late 

 Mr. Dutton's house and Greenwich, i6 m 28 s ,5. 



It is left for the public, and this learned Society in parti- 

 cular, to determine how far the near agreement of these several 

 methods, tends to corroborate the assertion I have advanced, of 

 the dependence which may be placed on the deductions drawn 

 from the observations made at Beachy Head and Dunnose. If 

 there had been only one watch employed on the occasion, the 

 result would not have been so satisfactory as the circumstance 

 of two being used seems to make it. As the occasion calls for 

 the remark, before I dismiss this article, I must observe, that 

 the highest advantages would accrue to geography, were the 

 ideas of the Astronomer Royal carried into execution, (and which 

 I shall endeavour to do at some future period,) respecting the 

 discovery of the difference of longitude between Greenwich 

 and some very remote point on the western side of the island, 

 (St. David's Head for instance,) by means of timekeepers, 



• According to Horwood's Map of London, the distance from the centre of St. Paul's 

 to Bolt Court, at the corner of which Mr. Dutton's house is situated, is 31 chains. 



