Cornish acre

In Cornwall, Great Britain, a unit of land area. Apparently the name was given to two and perhaps three different units, in overlapping periods of time.

1

In the 12th century, renaming of a much older unit, said to be on the order of 270 statute acres. It appears in legal documents (which were in Latin) as acras Cornubiensis terræ. The magnitude of the obligations imposed on those holding such a piece of property indicates that it must have been much, much, larger than a statute acre. The value of 270 statute acres appears to be traceable to an unpublished survey by Norden.

sources

Commonly thirtie Acres make a farthing land, nine farthings a Cornish Acre, and foure Cornish Acres, a Knights fee. But this rule is overruled to a greater or lesser quantitie, according to the fruitfulnesse, or barrennesse of the soyle.

Richard Carew.
The Survey of Cornwall,...
London: Printed for B. Law in Ave-Mary-Lane; and J. Hewett, at Penzance, 1769.
Page 36.

Following Carew, the Cornish acre would be 270 statute acres, and a knight's fee 1080 acres, which is a conceivable size. Carew also notes the Cornish acre of definition 3.

The Cornish, in adopting the Saxon word acre (æcer) applied it in the most extraordinary manner, either through utter ignorance of its meaning, or from an absurd attempt to designate by this term a previously existing measure of their own, between two and three hundred times as large.

...

The absurdly denominated old Cornish acre, is believed to contain 280 Norman acres.

Davies Gilbert.
The Parochial History of Cornwall founded on manuscript histories of Mr. Hals and Mr. Tonkin, with additions and various appendices. Vol. III.
London: Published by J. B. Nichols and Son, 1838.
Page 388.

2

In Cornwall, a unit of land area, about 60 statute acres.

examples

Robertus de Wena tenet tres acras Cornubiensis terræ in villa de Pengevel, in capite, de domino Rege, per serjantiam inveniendi quinque soldarios ad Vada Gayte Castri de Lanceveton, &c.

Pleas of the Crown de ann. 12 Edward I. Cornub. Blount, 55.

Robert de Wena holds three Cornish acres* of land in the town of Pengevel, in capite, of our Lord the King, by the serjeanty of finding five soldiers at the Gayte Fords of the Castle of Lanceveton, &c.

*Note, a Cornish acre of land makes sixty of our statute acres, or near thereabout.

Thomas Blount. Rev and corrected by Josiah Beckwith. Additions by Hercules Malebysse Beckwith.
Fragmenta Antiquitatis: or, Ancient Tenures of Land …
London: Printed by S. Brooke, Paternoster-Row, for Messrs Butterworth and Son, etc., 1815.
Page 129.

And of this place we further read (Carew's Survey) the 12th Edward I. its revenues was rated for twelve Cornish acres of land, that is to say, seven hundred and twenty statute acres...

[Joseph Polsue, editor.]
A Complete Parochial History of the County of Cornwall. Vol. III.
Truro: William Lake, Boscawen Street, 1870.
Page 258.

3

In Cornwall, by the 18th century, a unit of land area formed by applying the Cornish perch of 18 feet (instead of the English statute perch of 16½ feet) to the traditional definition of an acre (4 perches by 40 perches). The resulting acre = 5760 square yards, is slightly larger than a statute acre.

examples

So doth their Pearch exceed that of other Countries, which amounteth unto 18. foote. And it is likewise observed by strangers, that the Cornish miles are much longer than those about London, if at least the wearinesse of their bodies (after so painefull a journey) blemish not the conjecture of their mindes.

Richard Carew.
The Survey of Cornwall,...
London: Printed for B. Law in Ave-Mary-Lane; and J. Hewett, at Penzance, 1769.
Page 55.

[Discussing an erw of 5760 square yards] This erw is equivalent to the Cornish acre.

Walter Davies.
General View of the Agriculture and Domestic Economy of South Wales… Volume II.
London: Printed by B. McMillan, Bow-Street, Covent Garden: For Sherwood, Neely & Jones, Paternoster-Row; Tudor and Heath, Monmouth; etc., 1815.
Pages 503 & 504.

The Saxon acre in its true extent, was however adopted afterwards in Cornwall, consisting of one hundred sixty square poles, each eighteen feet long. The Normans for some reason quite unknown, reduced the length of the pole from eighteen to sixteen feet and a half, and thus established the difference between Saxon or customary, and Norman or statute acres. They differ in the proportion 18 squared to 16½ squared, or as 12 squared to eleven squared, that is as 144 to 121. As 6 to 5 for any approximate conversion, and as 25 to 21 very nearly. This Saxon acre continues, up to the present time, in very general use throughout Cornwall, and is the measure by which woodlands are estimated in most parts of England.

This fortified ground I examined in August 1792. It is an earthwork denominated Warren, containing six Cornish acres, as the farmer told me, or about seven statute acres.

In the measure of land, custom in Cornwall is more prevent than statute law. Mr. Norden, who was surveyor to Henry Prince of Wales and Duke of Cornwall, asserts that one Cornish acre formerly contained 270 statute acres. In the days of Dr. Borlase, the customary perch of land contained eighteen feet, while the statute perch contained only sixteen feet and half. The present dimensions of an acre of 160 square perch of 16½ feet were settled in the reign of Edward I.; and in the succeeding reign, 800 such acres made a knight's fee. The customary acre still prevails, though robbed of its extravagant dimensions; and in the sale of estates this is uniformly understood, unless the statute measure is particularly expressed.

Fortesque Hitchins, ed. by Samuel Drew.
The History of Cornwall, from the earliest records and traditions to the present time. Vol. 1.
Helston: Printed and published by William Penaluna, 1824.
Page 578.

examples

In Cornwall, according to an early fine which carefully states that the sum of half an acre and two ferlings equalled an acre, the ferling was the fourth part of a Cornish acre.¹ Its area of course varied as did that of the unit of which it was the fourth part. At Brixham, as we have seen, it contained 30 acres;² and at the end of the sixteenth century this was its size at Woodbrooke, at Allerton, and at Sherford.³ In a Devon fine of 22 Henry III three ferlings equalled 43 acres.⁴ In Cornwall, in 1337, the ferling was said to contain from 4 to 5 acres, the Cornish acre being only four times as great;⁵ but in a rental of 6 James I the Cornish acre was larger. three-fourths of it containing 70 English acres.⁶ Thus, at different times and in different places the ferling varied in extent between 4 and 30 English acres.

1. Ped. Fin., 31-2-20.
2. Cf. above, p. 259.
3. Rents. and Survs., Portf. 6/61; Add. MS 15. 21605, ff. 19, 24.
4. Ped. Fin., 40-12-226.
5. Sir John Maclean, The Parochial and Family History of the Deanery of Trigg Minor (3 vols., London, 1873-79), iii. 45 sq.
6. Rents. and Survs., Portf. 2133.

Howard Levi Gray.
English Field Systems.
Cambridge: Harvard University Press, 1915.
Page 264.

Gray was not much interested in the Cornish acre, but these miscellaneous gleanings are worth a look.

Brixham, Woodbrooke, Allerton and Sherford are all in Devon, not Cornwall, and these data suggest a unit of 120 statute acres. In regard to the Devon fine, note that if 3 ferlings are 43 acres, an acre is 57 statute acres, very near the 60-acre size discussed in definition 2.

The 16 to 20 acre claim for 1337 is puzzling. Unfortunately, we haven't yet been able to consult this book.