1- 8 1s set, cast and dance RH across with 3s
9-16 1s set, cast up and dance LH across with 2s
17-24 1s followed by 2s dance down, cast up behind 3s, in and dance up to top and 1s cast back to 2nd place
25-32 2s+1s dance R&L
(MINICRIB, Dance Crib compiled by Charles Upton, Deeside Caledonian Society, and his successors)
1-4 1s set and cast;
5-8 1s3s right hands across;
9-12 1s set and cast up;
13-16 1s2s left hands across;
17-24 1s, followed by 2s, lead down, cast up round 3s, meet, lead up to the top and cast, finishing with 2s at the top, 1s in 2nd place;
25-32 2s1s rights and lefts.
(MAXICRIB, Scottish country dancing instructions compiled by Reuben Freemantle)
The Sedan Chair
The dance and tune first appeared in a publication in 1772, long before the steam carriage or steam locomotive had been invented, and the word 'machine' at that time was often used for a horse drawn carriage in Scotland. Logically a machine without horses would be the carriage itself, without the horses. The sedan chair.
By the mid-17th century, sedans for hire were a common mode of transportation. In London, 'chairs' were available for hire in 1634, each assigned a number and the chairmen licensed because the operation was a monopoly of a courtier of Charles I. Sedan chairs could pass in streets too narrow for a carriage and were meant to alleviate the crush of coaches in London streets, an early instance of traffic congestion.
A similar system was later used in Scotland. In 1738, a fare system was established for Scottish sedans, and the regulations covering chairmen in Bath are reminiscent of the modern Taxi Commission's rules. A trip within a city cost six pence and a day's rental was four shillings. A sedan was even used as an ambulance in Scotland's Royal Infirmary.
The Chain Plough
The chain plough was pulled along the length of the field by a stationary steam engine and chain drums. These were moved along the ends of the field as ploughing progressed. However the earliest mention found of this device (which arguably is reflected in the crossing and hands across movements, if these are original) slightly post-dates Rutherford's 1772 publication. At least it would mark the potential ability to displace the horse in one of its traditional roles. Certainly the title is too early to refer to machine-powered transport.
For an alternative origin, Dr Walter M. Ligon, of RSCDS Atlanta Branch refers to the entry for 26 October 1769 in Boswell's Life of Johnson:
Dr. Johnson was in very good humour, lively, and ready to talk upon all subjects. Mr. Fergusson, the self-taught philosopher, told him of a new-invented machine which went without horses: a man who sat in it turned a handle, which worked a spring that drove it forward. 'Then, Sir, (said Johnson,) what is gained is, the man has his choice whether he will move himself alone, or himself and the machine too.'