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EXPLANATION OF THE PLATES. 
PLATES XXVII. and XXVIII. 4 
These plates are designed to illustrate Capt. Oliver’s paper on the supposed advan 
tages of sail on large sea-going steam vessels under various circumstances of unfavour 
able winds. Plate XXVII. represents a scale of different courses from the Cape of 
Good Hope to the Isle of France, with the several distances marked, and Plate 
XXVIII. represents four drawings of her Majesty’s steam ship Phoenix, in different 
positions with respect to the wind. 
PLATE XXIX. 
This plate exhibits the various situations of a trial at sailing of her Majesty’s steam 
ship of war Medea with the Caledonia, Vanguard, and Asia. For particulars see 
the end of Lieut. Baldock’s excellent Memoir of the Medea, Appendix, page 100. 
PLATE XXX. 
In 1816 a vessel (Caledonia) was purchased by Messrs. Boulton and Watt, and 
fitted with two engines of fourteen horses’ power, solely for the purpose of making 
experiments under various circumstances and modifications of paddle wheels. One 
of these experiments embraced the ascension of the Rhine in the winter of 1817 as 
high as Coblentz. 
The plate represents a side view of the engines manufactured by Boulton and 
Watt for the Red Rover and City of Canterbury steam vessels. This form of marine 
engine adopted by them about this period, say 1817 s was fitted on board the Fa 
vourite in April 1818, and, with the exception of some slight improvements principally 
made by themselves, it still remains unchanged. 
In the first edition of this work it was stated in mistake, that they had adopted it 
from the Clyde. This is incorrect, and we take the present opportunity of stating 
that this mode of construction is due to Boulton and Watt, and that a preference has 
been given to the arrangement by several of the best makers who have followed it.