Like other ancient peoples, the Irish fixed their standards of length - measures, for want of better, mostly, but not exclusively, with reference to parts of the human body. The troigid [tro-id] or foot was the length of a man's foot, which was counted equal to twelve ordlochs - thumb-measures or inches: so that this troigid was practically the same as the present English foot.
The following table of long measures, which is given in the Book of Aicill, may be taken as the one in most general use. The grain, i.e. the length of a grain of wheat of average size, was the smallest measure used by the Irish.
3 grains, 1 ordlach or inch
4 inches, 1 bas, palm, or hand
3 palms, 1 troigid or foot
12 feet, 1 fertach or rod
12 rods or fertachs, 1 forrach
12 forrachs in length by 6 forrachs in width, 1 tír-cumaile (i.e. 'cumal-land')
According to this table a tír-cumaile contained about 34 English acres; and it was so called because it was considered sufficient to graze a cumal, i.e. three cows.
When English ideas and practices began to obtain a footing in Ireland, after the Anglo-Norman Invasion, various other measures of land were adopted, the most general of which was the acre. Land was commonly estimated in acres and ploughlands according to the following table :-
120 acres, 1 seisrech [sheshera] or ploughland.
12 ploughlands, 1 baile, bally, or townland.
30 bailes, 1 tuath or tricha.
Various other length-measures were in use. A céim [kaim] or step was 2.5 feet. For small measures the bas [boss and the dorn [durn] were in constant use. The bas or ' palm ' was the width of the hand at the roots of the fingers, which was fixed at 4 inches. The dorn or ' fist,' with the thumb closed in, was 5 inches : with the thumb extended, 6 inches.
Lengths and distances were often roughly indicated by sound. For example, in connexion with the law of distress, certain distances, called in the Senchus Mór "magh-spaces," were made use of; and the old commentator defines a magh-space to be "as far as the sound of the bell [i.e. the small handbell of those times] or the crow of the barn-door cock could be heard." The crow of a cock and the sound of a bell, as distance-measures, are very often met with; and the ancient Germans also used them. Other vague modes of estimating lengths were used. The legal size of the faithche [faha] or green round a house depended on the rank of the owner; and the unit of measure was the distance a man could cast a spear standing at the house.
The standard unit of capacity adopted by the Irish was the full
of a hen-eggshell of moderate size, which perhaps was as good a standard as could be found at the time.
Beginning with this there is a regular table of measures of capacity.
Twelve eggshellfuls made a meisrín [messhereen], which contained
about as much as our present pint.
The smallest weight used was a grain of the best wheat. The following is the table of weight founded on the average grain of wheat :
8 grains, 1 pinginn or penny of silver.
3 pinginns, 1 screpall.
24 screpalls. - 1 unga or ounce.
The unga or ounce (576 grains of wheat or about 452 grains Troy) was the standard used in weighing metals. The word seems to have been borrowed from the Latin uncia : but there was an older native word, mann, for the ounce.
From numerous references in the old writings, we learn that the ancient Irish had balances of different kinds and sizes, and with different names. The most usual Irish term for a balance in general, and also for the beam of a balance, was meadh [ma], which is the word in use at the present day. A puincern [punkern : meaning 'notched beam'] was a sort of steelyard, i.e. a balance having a single weight moveable along a graduated beam from notch to notch, which by its distance from the suspension point indicated the weight of the commodity - identical with our modern steelyard.
In early stages of society in Ireland, as in all other countries, buying and selling and other commercial transactions ,were carried on by means of payment in kind: and there is hardly any description of valuable articles that was not used for this purpose. Payments were made for purchases, tribute, fines, &C., in cows, sacks of corn, salted pigs, butter, mantles, and soforth : the parties determining the values according to the customs of the place. But mixed up with this barter in kind, gold and silver, told out by weight, and - after the middle of the eighth century - silver coins, were used as mediums of exchange.
That the Irish were acquainted with the use of coined money, at least as early as the eighth century, is proved by the records: but whether they coined money for themselves before the tenth century is a matter that has not been determined. The coins in circulation among the Irish were the pinginn and the screpall [skreppal], both of silver. The pinginn weighed 8 grains of wheat, equal to 6 grains Troy: the screpall was equal to 3 pinginns, i.e. 18 grains Troy.
Many specimens of the pinginn and of the screpall are preserved in the National Museum. The pinginns are what are called "bracteate" coins, i.e. struck only on one side ; but the screpalls are impressed on both sides.
From the very beginning of our records gold and silver were used as a medium of exchange, sometimes as ingots, but more commonly in the form of rings, bracelets, and other ornaments. They were weighed by the ounce, which, as we have seen, was equal in weight to 576 grains of wheat, or to 432 grains Troy. In order to facilitate interchange of this kind, gold and silver rings of various forms, as well as other gold and silver ornaments, were generally or always made of definite weights. Notices of this custom are found everywhere in Irish literature. So also Caesar records that in his time the people of Britain "used brass or iron rings fixed as at a certain weight as their money." But in Ireland, gold, as being comparatively abundant, was used instead of the inferior metals.
The custom of making gold ornaments after a fixed weight seems to have been general among all civilised nations of antiquity.
It may be considered certain that in Ireland the open gold rings called bunne-do-at (now often called fibulae: articles), were used as money. But besides those as well as other gold ornamental called bunne-do-at, there are in the National Museum a great number - fifty or more - of very small open gold rings, from 1/4 to 3/4 inch in diameter, without the terminal knobs or ats : these are bunnes simply, not bunne-do-ats. From their great numbers, and from their simple, unornamental construction, they have all the appearance of having been used mainly as currency.
A full-grown cow, or ox, was in ancient times a very general standard of value, not only in Ireland, but all over the civilised world : and was considered equal in value to one ounce of gold. In this use - as an article of general payment -a cow was in Ireland generally called a séd [shade]. Cows or séds were very often used both in actual payments and in estimating amounts. Next above the séd was the cumal which was originally applied to a bondmaid but the word came to be used very generally to signify the value of a bondmaid, which was counted as three séds, or cows.
A miach or sack of corn - generally of oats or barley - which for convenience sake must have been always made of uniform size - was very often used as a standard of value : it is indeed adopted in the Brehon Law as the almost universal standard in estimating fines for trespass, and payments for grazing.
The Irish divided their year into quarters. The four quarters were called Earrach [arragh], Spring ; Samhradh [sowra], Summer ; Foghmhar [fowar], Autumn ; Geimhridh [gevre], Winter : and they began on the first days of February, May, August, and November, respectively. We have historical testimony that festivals with games - which will be described in chapter xxv. - were celebrated at the beginning of Summer, Autumn, and Winter ; but we have no account of any such celebrations at the beginning of Spring. These divisions of the year and the festivities by which they ushered in originated with the Pagan Irish, and were continued into Christian times.
The 1st February, the beginning of Spring, was called Oimelc, signifying 'ewe-milk,' ''for that is the time the sheep's milk comes '' : but this day is now universally known among Irish speakers as Féil Bhrighde [Fail Vreeda], ' St. Brigit's festival,' the old Pagan name Oimelc, being obsolete for centuries.
The first day of May was the beginning of Summer. It was called Belltaine or Beltene [beltina] ,(modern - Bealtaine) which is the name for the 1st May still always used by speakers of Irish ; and it is well known in Scotland, where Beltane has quite taken its place as an English word.
"Ours is no sapling, chance sown by the fountain,
Blooming at Beltane, in winter to fade.''Lady of the Lake
The 1st of August, the beginning of Autumn, was, and is still, called Lugnasad [Loonasa] , from the nasa or games instituted by the Dedannan king Lug [Loo] of the Long Arms, which were celebrated at Tailltenn yearly on that day.
Samhain or Samhuin [sowin], the first of November, was the first day of Winter. This name is still used even among the English-speaking people in Scotland and the north of Ireland, in the form of sowin or sowins, which is the name of a sort of flummery usually made about the 1st November.
You'll find a rather nice Celtic calendar at http://www.paxconsulting.com/moonth.html
The ancient Irish counted time rather by nights than by days. Thus in the Life of St. Fechin we are told : -" Moses was forty nights on Mount Sinai without drink, without food." In coupling together day and night they always put the night first: in other words, the night belonging to any particular day was the night preceding; so that what they called Sunday night was the same as Saturday night with us.