Problems of Nautical Astronomy. 
119 
ADDITION. 
Gontenant line Methode pour reduire les Distances lu- 
naires. Par Mr. H. Cavendish, Membre de la 
Societe Royale , kc. 
Mr. Cavendish m’ayant fait fhonneur de me communiquer 
la methode qu’il a trouv6 pour reduire les distances lunaires, je 
profite de la permission de ce savant, pour la faire connoitre 
au public, en pla£ant ici un extrait de ce qu’il m’a ecrit a ce 
sujet, dans les propres mots de hauteur. 
Extract of a Letter from Henry Cavendish, Esq. to Mr. 
Mendoza y Rios, January , 1795. 
“ The methods in which the whole distance of the moon and 
star is computed, particularly yours, require fewer operations 
than those in which the difference of the true and apparent 
places is found ; but yet, as in the former methods, it is neces- 
sary either to take proportional parts, or to use very voluminous 
tables ; I am much inclined to prefer the latter. This induced 
me to try whether a convenient method of the latter kind might 
not be deduced from the fundamental proposition used in your 
paper, and I have obtained the following, which has the advan- 
tage of requiring only short tables, and wanting only one pro- 
portional part to be taken, and I think seems shorter than any 
of the kind I have met with. 
“ Let b and H be the apparent and true altitude of the star; 
