This is the entry taw, sb.² from The Oxford English Dictionary, 2nd ed. (1989) [pronunciation omitted because I cannot make an inverted "c"]:

taw, sb.² Also 8 tau, 9 tor. [Origin unascertained, and order of senses uncertain: perh., like alley, ALLY sb.², an abbreviation.]

a. A large choice or fancy marble, often streaked or variegated, being that with which the player shoots.
1709 STEELE Tatler No. 30 ¶1 He is hiding or hoarding his Taws and Marbles. a1761 CAWTHORN Wit & Learn. Poems (1771) 48 He minded but his top, or taw. 1807, 1833 [see ALLY sb.²]. 1837 DICKENS Pickw. xxxiv, After enquiring, whether he had won any alley tors or commoneys lately. 1843 THACHERAY Irish Sk. Bk. xxiv, Large agate marbles or 'taws'. a1845 HOOD Clapham Acad. xiv, Five who stoop The marble taw to speed. 1857 HUGHES Tom Brown I. iii, His small private box was full of peg-tops, white marbles (called 'alley-taws' in the Vale), [etc.]. 1876 GRANT Burgh Sch. Scotl. II. v. 179 A still greater favourite is shooting a 'taw', which requires no small dexterity.

b. transf. A game played with such marbles.
1709 STEELE Tatler No. 112 ¶3 A Game of Marbles, not unlike our modern Taw. 1784 COWPER Tiroc. 307 To kneel and draw The chalky ring, and knuckle down at taw. 1798 Sporting Mag. XII. 169 At cricket, taw, and prison-bars, He bore away the bell. 1840 THACKERAY Paris Sk.-bk. (1869) 45, I would lay a wager that...their school learning carried them..only to the game of taw.

c. The line from which the players shoot in playing the game. Hence in phrases: see quots.
1740 DYCHE & PARDON s.v. Knuckle, They frequently say, Knuckle down to your taw, or fit your hand exactly in the place where your marble lies. 1840 Spirit of Times 7 Mar. 6 We have understood that Boston..will be en route for the stable..at Columbia, South Carolina--that is, if Wagner 'comes to taw'. 1854 MISS BAKER Northampt. Gloss. s.v., 'Shoot from taw'. 'You don't stand at taw'... 'If you don't do so and so I'll bring you to taw'. 1868 in Amer. Speech (1965) XL. 132 He smiles at all the girls he meets, And you smile at him on the crowded streets, Why don't you make him 'come to taw', I know he wants a mother-in-law. 1881 Leicesters. Gloss. s.v., A ring is scratched on the ground, and at some distance from it a straight line called taw. Ibid., We thus get the phrase..'come up to scratch' and 'come up to taw'. 1904 W.H. HARBEN Georgians xxxii. 292 His wife's a bully woman; she fetched 'im to taw. 1934 D. RUNYON in Collier's 3 Mar. 41/1 Georges takes a wonderful liking to Princess O'Hara right from taw. 1935 H. DAVIS Honey in Horn ix. 113 The only way Mrs. Yarboro could tell anything was start from taw. 1956 Coast to Coast 183 Starting off from taws with a big load to carry. 1969 Sunday Truth (Brisbane) 5 Oct. 14/4 Without a share of overseas star shows, Seven has been battling from taws, but..is..getting stuck into the other networks with a 'super-specials' policy change.

~Masato