Note the slight difference near the greyhound's tail. There are other marks used by Messrs. Boote. At www.thepotteries.org: T & R BOOTE were manufacturers of earthenware, ironstone, etc at Burslem starting from 1842. Early marks consisted of the firm's name or initials, and the word England was added in 1891, with the greyhound being a standard mark from 1890 to 1903. I think these shards are prior to the word England being added, so thus around 1890.
In the book Ceramic Art in Great Britain (see more below): "The marks used by Messrs. Boote are on their white granite ware, the impressed initials T & R B; and the following printed in black, viz.- and another bearing the crest, a greyhound couchant, collared and slipped between two laurel wreaths, and the words: T & R BOOTE, ROYAL PREMIUM IRONSTONE, and above the words TRADE MARK. On the tiles the name is raised in letter T & R BOOTE, BURSLEM."
See books.google.com for more information. Ceramic Art in Great Britain, LLewellynn Jewitt, Vol. II, 1878, Chapter VI, pg.256-257 in the original book.
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