Definition of "millstone"

As it is the circular Motion of the Mill-ſtone which brings the Corn out of the Hopper by Jerks, and with a Velocity depending upon that of the Stone, other Grains are always ſucceeding, which raiſe it anew, and the Flower just made being no longer preſs'd is carry'd away into the Boulting Mill by the Circulation of Air that the Mill-ſtone puts into motion, which makes a whirling there.

1744, J[ohn] T[heophilus] Desaguliers, “Lecture XII. On Engines, especially Hydrostatical and Hydraulick Machines.”, in A Course of Experimental Philosophy, volume II, London: Printed for W. Innys, at the West End of St. Paul's; M. Senex, in Fleet-street; and T[homas] Longman, in Pater-noster-Row, page 429

The reason why a mill-stone signifies confirmation from the Word in both senses, is, because wheat signifies good, and fine flour the truth thereof, hence by a mill-stone, by which wheat is ground into fine flour, or barley into meal, is signified the production of truth from good, or the production of what is false from evil, thus also the confirmation of truth or what is false from the Word; […]

1815, Emanuel Swedenborg, “[Book of Revelation,] Chapter XVIII”, in John Clowes, transl., The Apocalypse, or Book of Revelations, Explained According to the Spiritual Sense; in which are Revealed the Arcana which are there Predicted, and have been hitherto Deeply Concealed: Translated into English from a Latin Posthumous Work, of the Honourable Emanuel Swedenborg [by William Hill]; and Revised by the Translator of the Arcana Cœlestia [John Clowes], volume VI, London: Printed and sold for the Society for Printing and Publishing the Works of the Hon. Emanuel Swedenborg, instituted in London in the year 1810; by E. Hodson, 15, Cross Street, Hatton Garden; sold also by T. Goyder, 8, Charles Street, Westminster; and may be had of all booksellers in town and country, page 149, paragraph 1182

We can tell what Australopithecines ate from the remains of their jaws and teeth. The earliest finds show teeth which are large and round like millstones – acting as grinding and pulverizing machines for fibrous vegetation.

1998, Colin Spencer, “Aquatic Ape Theory. How Early Did Fish Enter the Diet?”, in Harlan Walker, editor, Fish: Food from the Waters: Proceedings of the Oxford Symposium on Food and Cookery 1997, Totnes, Devon: Prospect Books, page 307

In North America the millstone grit, and a grey sandy and slaty rock beneath it, occur three times; and it is exceedingly difficult to distinguish these rocks in hand specimens, without the aid of organized remains. And remains are almost exclusively confined to the grey rocks. Common quarrymen, farmers, and foreign geologists, apply the names, greywracke and millstone, to all these rocks promiscuously; neither having observed their different relative positions.

1832, Amos Eaton, Geological Text-book, for Aiding the Study of North American Geology: Being a Systematic Arrangement of Facts, Collected by the Author and His Pupils, under the Patronage of the Hon. Stephen Van Rensselaer, 2nd edition, Albany, N.Y.: Published by Websters and Skinners, New York, N.Y.: G. and C. and H. Carvill, Troy, N.Y.: William S. Parker, N. Tuttle, printer, pages 92–93

From the above account it will be seen how closely the Millstone Grit and the Lower Coal Measures are like one another in their lithological character. Each is a group of thick sandstones parted by shales, and in each beds of coal are very generally found on the top of the sandstones. The differences are these. Among the Millstones the sandstones are thicker, fewer, further apart, more constant both in size and character, and as a rule coarse grits or conglomerates.

1869, A. H. Green, C[lement] le Neve Foster, J. R. Dakyns, “Lower Coal-measures or Ganister-beds”, in The Geology of the Carboniferous Limestone, Yoredale Rocks, and Millstone Grit of North Derbyshire and the Adjoining Parts of Yorkshire. (Sheets 81 N.E., 81 S.E., 72 N.E., and Adjoining Parts of 88 S.E., 82 N.W., 82 S.W., and 71 N.W. of the Map of the Geological Survey.) (Memoirs of the Geological Survey of England and Wales), London: Printed for Her Majesty's Stationery Office; published by Longmans, Green and Co., page 11

[H]owever great and powerful England may be, the strain of such entanglements cannot but tell on her, and one day she may find herself in a predicament in which India may simply hang as a mill-stone round her neck.

1905, Pherozeshah M[erwanjee] Mehta, “Speech on the Ilbert Bill”, in C[hirravoori] Y[ajneswara] Chintamani, editor, Speeches and Writings of the Honourable Sir Pherozeshah M. Mehta, K.C.I.E., Allahabad: The Indian Press, page 164

Furthermore, Colonel [Josiah Clement] Wedgwood was dead against special representation being given to landlords or even to universities. "Let India beware," he declared, "of the expansion of communal representation which she will find as a mill-stone hanging about her neck which will grow heavier as time goes on."

, “Britain and India”, in Josiah C. Wedgwood: The Man and His Work, Madras: S. Ganesan & Co., page 118

Another millstone around the NDP’s neck was the relative lack of seasoned parliamentarians in the government front bench who were skilled enough at repartee to take on the Tory veterans across the floor.

1982 December 11, Frances Russell, “Economic performance buoys Pawley’s position”, in The Vancouver Sun (The Weekend Sun), Vancouver, BC, page A6

That stunning defeat effectively ushered in a three-year deep freeze on any discussion of climate in Congress, an era of paralysis so pervasive that in June 2013, in what many environmentalists hailed as a milestone for action on climate and critics decried as a millstone around the neck of a struggling economy.

2015, Seamus McGraw, “The Other White Meat”, in Betting the Farm on a Drought: Stories from the Front Lines of Climate Change, Austin, Tex.: University of Texas Press, page 67

AI may be a millstone to countries with a large population, they are a boon to a shrinking one.

2023 September 23, Leo Lewis, “It takes a village”, in FT Weekend, Life & Arts, page 2