Trigonometrical Survey. 673 



from whence, after a similar correction with that just made, we 

 find the distance of 



the Windmill 256304 "1 feet from the f 143597 "1 feet from the perpendicular of 

 the Flagstaff 260152 J meridian, and \ 140876/ St. Agnes. 



From the same page, and the data furnished in this work, 



we also find the bearing of . 



St. Agnes Light- fSennen - 68° 6' 54" S W 



House from |St. Buryan 69 5 56 S W; which gives 



2 ^ 5 o ^ [feet, for the distance from the meridian, and 

 265879/ 



1 ^ % [feet, for the distance from the perpendicular of St. Agnes. 



The mean of the first is 265872 feet, and the mean of the last, 

 when corrected, 149133 feet. 



With the above data, and also the latitude and longitude of 

 St. Agnes, we get 



{Day-mark in St. Martin's A 49 58'2",o. 

 Windmill St Mary's - - 49 54 3*>7 



Flagstaff, ditto - - 49 54 59,1 



St. Agnes Light-House* - - 49 S3 3^,8 



In Time. 



r Day.mark 1° z'43',1 1 from the meri . f 6° 14' 38",8 24-58^6 



and longitude west I Windmill 1 5 3,2 I™ ™ e ™ eri I 6 16 58 ,7 25 7 , 9 



from St. Agnes, i Flagstaff 1 6 2,7 f . ? or T|t ""j 6 17 57,4 25 11 ,9 



iLightHouse 1 7 27,7 J W1C ' {6 19 23,4 25 21 ,5 



• In the Requisite Tables, published by order of the Board of Longitude, the lati- 

 tude of the Scilly Lights is said to be 49 56'o ff , and longitude 6° 46' o". The 

 latitude, according to the survey, is 49 53' 36",8, and longitude 6° I9'23*,4. An 

 error of 2' 23' in the latitude, may not perhaps be considered extraordinary; but 

 how, in a maritime country, like our own, where chronometers are in such constant use, 

 so great an error as 26' 37" (i m 46 s ! in time) in the longitude, should have remained 

 undetected, excepting by one person, is surprising. J. Huddart, Esq. visited the 

 Scilly Isles, having with him a watch made by Arnold, and obtained his time at 

 that spot in the island of St. Mary where the body of Sir Cloudsley Shovel 

 is said to have been thrown ashore, by means of equal altitudes of the Sun's limb; 

 he then found, comparing his time with that shewn by the watch, that o h 25 m 18* was 

 the difference between the meridians of Greenwich and this spot in St. Mary's. Now 

 St. Agnes Light-house is about 2' of a degree west of the place to which Mr. Huddart 

 alludes ; therefore, 25' 18" + 8" zz 25*26" is the longitude of St. Agnes, through these 

 means ; which differs only 4',5 in time from that found by the survey. 



