One of the chief dangers in a wool cargo is spontaneous combustion. This caused the end of several fine ships, such as the _Fiery Star_ and the new Orient liner _Aurora_. Spontaneous combustion was likely to happen if the bales were wet or damp, either when loaded or through contact with other damp cargo, dunnage, ballast or even sweating water tanks. Often enough the wool got a wetting on its way to the ship, and though possibly afterwards sun-dried on the outside of the bales, so that to all appearances it was perfectly dry, was really damp inside and very inflammable. Some Australian wool growers contended that the practice of clipping sheep in the morning when the fleeces were heavy with dew was a cause of spontaneous combustion. Wool, of course, being a very light cargo, requires stiffening, but hides, tallow, etc., were generally used as deadweight, also copper ore. A ship with a wool cargo was reckoned to require two-thirds of the ballast necessary when in ballast only. Wool freights in the early days were 1d. per lb., and gradually fell to a farthing per lb.—this was for washed wool: the freight for greasy wool, which had not been cleaned and was therefore heavier than washed wool, being about 25% less. The Aberdeen White Star Line. Amongst the pioneers of the trade with the Colonies George Thompson, of the Aberdeen Clipper Line, known to generations of Australians as the Aberdeen White Star Line, holds a foremost place. The history of this celebrated firm dates back to the year 1825, when its first representative, a clipper brig of 116 tons named the _Childe Harold_, was sent afloat. It may safely be said that from that hour the Aberdeen White Star Line has never looked back. From the first it earned a reputation for enterprise and good management. Amongst its fleet were numbered some of the earliest clipper ships built in the United Kingdom, ships whose records were worthy to rank with those of the celebrated Black Ball and White Star Lines; and which in their liberal upkeep had little to learn from even such aristocrats of the sea as the Blackwall frigates. Until the discovery of gold, the green clippers ran regularly to Sydney, but when all the world began to take ship for Melbourne, the port of the gold region, it was only natural that some of the Aberdeen White Star ships should be put on the Melbourne run, and from that date the little flyers from Aberdeen were as well known in Hobson’s Bay as Sydney Cove. The ships were all built in the yard of Walter Hood, of Aberdeen, in whose business Messrs. Thompson held a large interest, and were all designed by Walter Hood with the exception of the celebrated _Thermopylae_. George Thompson, who founded the line, was joined, in 1850, by his son-in-law the late Sir William Henderson, and later on Mr. Thompson’s sons, Stephen, George and Cornelius, came by turns into the partnership.