DOI Page / Citation link:
https://doi.org/10.11588/diglit.12654#0243
A P P E N D I X.
LETTEK FROM THE ASTRONOMER ROYAL, IN REPLY TO ONE
FROM THE AUTHOR OF THE PRESENT WORK.
Royal Observatory, Greenwich,
April 26, 1850.
Sir,
I am enabled now to give you the result of calculations ap-
plying to the questions proposed in your letter of the 15th instant,
with accuracy greater than is required in such investigations. The
form of these computations is somewhat unusual to my assistants,
and some delay has therefore been occasioned by the necessity of
my looking to the calculations myself.
The modern places of the stars have been converted into longi-
tude and latitude, they have then been carried backwards by a pro-
cess which necessarily includes their proper motions, and then with
the proper values of obliquity they have been reconverted into right
ascensions and north polar distances. This process is rigorously
accurate.
The places of the Sun have been computed by Delambre's Tables,
applying the equation of the center. All the equations omitted
would not produce 1 minute of arc in the Sun's place. The cal-
culations have been checked by computations from Carlini's Tables.
The results of Carlini's (which are probably the more accurate) differ
3 or 4 minutes from Delambre's: but I have preferred to retain
Delambre's because they are given for the Paris midnight com-
mencing the civil day, for which time also my lunar places are com-
puted.
The places of the Moon have been computed from Damoiseau's
Tables, applying the five principal equations (equation of center,
evection, variation, annual equation, reduction for inclination). The
equations omitted may perhaps amount to 5 or 6 minutes. The
time is the Paris midnight commencing the civil day.
LETTEK FROM THE ASTRONOMER ROYAL, IN REPLY TO ONE
FROM THE AUTHOR OF THE PRESENT WORK.
Royal Observatory, Greenwich,
April 26, 1850.
Sir,
I am enabled now to give you the result of calculations ap-
plying to the questions proposed in your letter of the 15th instant,
with accuracy greater than is required in such investigations. The
form of these computations is somewhat unusual to my assistants,
and some delay has therefore been occasioned by the necessity of
my looking to the calculations myself.
The modern places of the stars have been converted into longi-
tude and latitude, they have then been carried backwards by a pro-
cess which necessarily includes their proper motions, and then with
the proper values of obliquity they have been reconverted into right
ascensions and north polar distances. This process is rigorously
accurate.
The places of the Sun have been computed by Delambre's Tables,
applying the equation of the center. All the equations omitted
would not produce 1 minute of arc in the Sun's place. The cal-
culations have been checked by computations from Carlini's Tables.
The results of Carlini's (which are probably the more accurate) differ
3 or 4 minutes from Delambre's: but I have preferred to retain
Delambre's because they are given for the Paris midnight com-
mencing the civil day, for which time also my lunar places are com-
puted.
The places of the Moon have been computed from Damoiseau's
Tables, applying the five principal equations (equation of center,
evection, variation, annual equation, reduction for inclination). The
equations omitted may perhaps amount to 5 or 6 minutes. The
time is the Paris midnight commencing the civil day.