360 



CATALOGUE. PRACTICAL ASTPONOMV, GEOGRAPHV. 



Mallet's mathematical description of the 



eaitli. R. S. 

 Ruinovski on the length of the pendulum. 



N. C. Petr. XVI. 567. 

 Roj's remarks on the figure of the earth. Ph. 



tr. 1777. 766. 

 *Roy's account of the measurement of a base 



on Hounslow heath. Ph. tr. 1785. 385. 



A base from Hampton pooihouse to Crantord bridge was 

 measured as a foundation for the comparison of the situa- 

 tions of London and Dover : the measurement was in a di- 

 rection a little inclined to the horizon, but the reduction 

 was only half an inch ; the length was found 27404.7 feet 

 by the glass rods. 



*Roy on the mode of determining the rela- 

 tive situations of Greenwich and Paris. 

 Ph.tr. 1787. 188. 



Comparison of the French observations. Proposes a base 

 of verification in Romney marsh. Table of degrees in va- 

 rious directions according to Bouguer's hypothesis, 2-28 ; 

 corrections, 465. 



Roy on the meridians of Greenwich and Pa- 

 ris. Ph.tr. 1790. 111. 



The French committee consisted of Cassini, M^chain, 

 and Legendre. Abase of verification of 28532.92 feet was 

 measured in Romney marsh with the steel chain : differing 

 only 9 inches from the calculation of the triangles founded 

 on the base in Hounslow heath : the chain appears to de- 

 serve equal confidence with the glass rods : it was length- 

 ened .023 inch in 100 feet by 6 weeks wear. The white 

 lights were found the best objects for nocturnal observa- 

 tions. The measurements on the different sides of the 

 channel agreed within 7 feet in 39800. The longitude of 

 Paris 2° 19' 42", or o' 18".8 in time E.of Greenwich. 



Roy on spherical and spheroidical triangles. 

 Ph. tr. 1790. 168, 192. 



Prontfs translation of Roy's memoir on the 

 measurement of a base. 4. Paris, 1787. 



Legendre on trigonometrical operations. A. 

 P. 1787. 352. 



Legendre Operations pour la junction des ob- 

 servatoires. 4. Paris. R. S. 



Dalby on the longitudes of Dunkirk and Pa- 

 ris. Ph.tr. 1791.236. 



The correct longitude of Paris 2° 20' 4''.o according to 

 Newton's ellipsis, or 9' ao".4 in time ; according to another, 

 dividing the errors, 9' 19". 7. Maskelyne from astronomi- 

 cal observations gives 9' 50*. 



Account of a survey by Williams, Mudge, 

 and Dalby. Ph. tr. 1*95.414. 

 The base on Hounslow heath was measured again with a 

 chain, and found 27404.3155 feet: the former measure- 

 ment, with some corrections which had been omitted, 

 27404.0843 ; a mean between both 27404.2 ; the base in 

 Romney marsh corrected was found 28534^ f. agreeing 

 thus with the base on Hounslow heath, and within an inch 

 or two, with another of 36574.4 feet measured on Salisbury 

 plain. 



Williams, Mudge, and Dalby on the conti- 

 nuation of the survey. Ph.tr. 1797. 432. 



Mudge's continuation of the trigonometrical 

 survey. Ph. tr. 1800. 539. 



Measurement of a base on Sedgmoor, of 27680 feet. 



Mudge on the measurement of an arc from 

 Dunnose to Clifton. Ph.tr. 180,3. 383. 



A new base of verification measured with the chain at 

 the extreme point of the survey. 



Laplace on the figure of the earth. S. E. 



1773. 503. A. P. 1783. 17. 

 Laplace Exposition du systcme du monde. 



Mecanique celeste. 

 Dionis du Sejour on geodetic calculation. 



A. P. 1778.73. H. 28. 

 Hubius de figura telluris. 4. Gott. 

 Gerlach Bestimmung dergestalt dererde. 8. 



Vienna, 1782. R.S. 

 Achard Schriften. 197. 

 De Luc Lettres physiques et morales, xlv, 

 Lalande on the ellipticity of the earth. A. P. 



1785. 1. Bode's Jahrbuch. 1791- 

 Lalande on Fernel's measurement of the earth 



published in 1528. A. P. 1787. 216. 



Makes it 57070 toises, only a toise more than the later 

 measures. In Ph. tr. X. it is called 56746. 



Klostermann's remarks on diflFerent mea- 

 surements. Gott. anz. 1785. 1786. 1789. 



