vigesimal counting was universal among Celtic races, this explanation is
quite gratuitous. The reason why the Celts used this method is entirely
unknown, and need not concern investigators in the least. But the fact that
they did use it is important, and commands attention. The five Celtic
languages, Breton, Irish, Welsh, Manx, and Gaelic, contain the following
well-defined vigesimal scales. Only the principal or characteristic
numerals are given, those being sufficient to enable the reader to follow
intelligently the growth of the systems. Each contains the decimal element
also, and is, therefore, to be regarded as a mixed decimal-vigesimal
system.

IRISH.[329]

10. deic.
20. fice.
30. triocad = 3-10
40. da ficid = 2-20.
50. caogad = 5-10.
60. tri ficid = 3-20.
70. reactmoga = 7-10.
80. ceitqe ficid = 4-20.
90. nocad = 9-10.
100. cead.
1000. mile.

GAELIC.[330]

10. deich.
20. fichead.
30. deich ar fichead = 10 + 20.
40. da fhichead = 2-20.
50. da fhichead is deich = 40 + 10.
60. tri fichead = 3-20.
70. tri fichead is deich = 60 + 10.
80. ceithir fichead = 4-20.
90. ceithir fichead is deich = 80 + 10.
100. ceud.
1000. mile.

WELSH.[331]

10. deg.
20. ugain.
30. deg ar hugain = 10 + 20.
40. deugain = 2-20.
50. deg a deugain = 10 + 40.
60. trigain = 3-20.
70. deg a thrigain = 10 + 60.
80. pedwar ugain = 4-20.
90. deg a pedwar ugain = 80 + 10.
100. cant.

MANX.[332]

10. jeih.
20. feed.
30. yn jeih as feed = 10 + 20.
40. daeed = 2-20.
50. jeih as daeed = 10 + 40.
60. three-feed = 3-20.
70. three-feed as jeih = 60 + 10.
80. kiare-feed = 4-20.
100. keead.
1000. thousane, or jeih cheead.

BRETON.[333]

10. dec.
20. ueguend.
30. tregond = 3-10.
40. deu ueguend = 2-20.
50. hanter hand = half hundred.
60. tri ueguend = 3-20.
70. dec ha tri ueguend = 10 + 60.
80. piar ueguend = 4-20.
90. dec ha piar ueguend = 10 + 80.
100. cand.
120. hueh ueguend = 6-20.
140. seih ueguend = 7-20.
160. eih ueguend = 8-2