F = 6 × 1021 tons × (4π² × 92 × 106 miles) / (365 ¼ days)²
which of course is a mass multiplied by an acceleration. The acceleration is—
(40 × 92 × 106) / 133300 × (24)² miles per hour per hour
= (3680 × 106 × 5280) / 133300 × 576 × (3600)² feet per sec. per sec.
= (115 × 5280) / 133300 × 576 × 12·96 × 32 feet per sec. per sec.
= g / 1640
Hence the Force of attraction is that which, applied to the earth's mass, produces in it an acceleration equal to the 1/1640th part of what ordinary terrestrial gravity can produce in falling bodies; or
F = 6 × 1021 tons × g / 1640
= 6 / 1640 × 1021 tons weight;