Forge comma

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Interval information
Ratio 1640558367/1638400000
Factorization 2-19 × 314 × 5-5 × 73
Monzo [-19 14 -5 3
Size in cents 2.2791622¢
Name forge comma
FJS name [math]\text{d2}^{7,7,7}_{5,5,5,5,5}[/math]
Special properties reduced
Tenney height (log2 n⋅d) 61.2212
Weil height (max(n, d)) 1640558367
Harmonic entropy
(Shannon, [math]\sqrt{n\cdot d}[/math])
~2.42098 bits
Comma size unnoticeable
open this interval in xen-calc

The forge comma is the 7-limit unnoticeable comma 1640558367/1638400000, which measures roughly 2.28 cents. It's notable as the interval separating the amity comma from the gamelisma. This comma was first found as the 7-limit comma linking 12edo, 34edo and 159edo. The various 11-limit families that temper out this comma are named after various metal objects made in a forge, hence the Forge as the name of this collection of temperaments.