Roundarm trial matches

The roundarm trial matches were a series of cricket matches between Sussex and All-England during the 1827 English cricket season. Their purpose was to help the MCC, as the game's lawgivers, to decide if roundarm bowling should be legalised or if the only legitimate style of bowling should be underarm, which had been in use since time immemorial.
Conditions of play.
The matches were also known as the "Experimental Matches". The conditions set for the matches allowed William Lillywhite and Jem Broadbridge of Sussex to bowl roundarm, while the All-England bowlers had to bowl underarm.
Summary of series.
Sussex won the first match at Sheffield against an all-professional All-England team by 7 wickets and the second at Lord's by 3 wickets. After the second match, the following declaration was made by some of the All-England players: 
"We, the undersigned, do agree that we will not play the third match between All-England and Sussex, which is intended to be played at Brighton in July or August unless the Sussex bowlers bowl fair – this is, abstain from throwing". 
It was signed by Tom Marsden, William Ashby, William Mathews, William Searle, James Saunders, Thomas Howard, Will Caldecourt, Fuller Pilch and Thomas Beagley. The declaration was later withdrawn and the third match was played at Brighton as planned. This time England won by 24 runs.
Match details.
Match 1 – All-England v Sussex at Darnall New Ground, Sheffield (4, 5 & 6 June 1827)
Match 2 – All-England v Sussex at Lord's Cricket Ground (18 & 19 June 1827)
Match 3 – Sussex v All-England at Royal New Ground, Brighton (23, 24 & 25 July 1827)
Lillywhite and Broadbridge bowled roundarm again despite the opposition of some All-England players, but the All-England side itself used roundarm in this game as George T Knight was a supporter of it and subsequently did much to have it legalised.
Conclusion.
The result of the "trial" was inconclusive and it was many years before roundarm was formally legalised. But, in practice, roundarm "was" adopted in 1827 as its practitioners, especially Broadbridge and Lillywhite, continued to use it with little, if any, opposition from the umpires.
Aftermath.
In 1828, MCC modified Rule 10 of the Laws of Cricket to permit the bowler's hand to be raised as high as the elbow.
In 1835, powerless to prevent the use of roundarm, MCC finally amended the Laws of Cricket to make it legal. The relevant part of the Law stated: "if the hand be above the shoulder in the delivery, the umpire must call "No Ball"." Bowlers' hands now started to go above the shoulder and the 1835 Law had to be reinforced in 1845 by removing benefit of the doubt from the bowler in the matter of his hand's height when delivering the ball.