Lightning was the first of a famous quartet of clippers designed and built by Donald McKay at East Boston, Massachusetts. Ordered for the Black Ball Line of Australian packets, she was registered at 2,083 tons and measured 243 feet in length with a 44 foot beam. Primarily a passenger ship, she had capacity for about 370 persons and carried a crew of 87. Clearing Boston on her maiden voyage in February 1854, she made a good run to Liverpool and thence to Melbourne in 77 days, returning in 64 days, a particularly fast time for the return passage. She soon became renowned for her excellent time-keeping and was one of the clippers chartered by the British government to ferry troops to India following the outbreak of the Mutiny in 1857. Despite the growing reliability of steam, Lightning remained an extremely popular ship throughout the 1860s until destroyed by fire at Geelong, Australia, in October 1869.
Thessalus, widely considered to be one of the fastest iron full-riggers ever launched, was ordered by A. & J.H. Carmichael & Co. and built for them by Barclay, Curle at Glasgow in 1874. Registered at 1,865 tons gross (1,782 net) and measuring 269 feet in length with a 41 foot beam, she was a magnificent main skysail clipper and boasted a sail plan regarded by her contemporaries to be 'perfect'. Although a familiar sight on the Australian wool run, she was also well-known in Calcutta and San Francisco, turning in excellent passages wherever she went. Her best time home from Australia was 75 days in 1896 and after a long and hugely successful trading career, she was sold to Swedish owners in 1905, still rated 100A1 by Lloyd's Register and reportedly in splendid condition.