Mr Logan on the Habits of Testaceous Molhisca. 47 



per hour, — a rate which has hardly been exceeded by the 

 most improved modern steamers, in canal waters. 



The expense of this experiment having exceeded the esti- 

 mates, Mr Miller became dissatisfied, and declined to proceed 

 any farther, nor could he ever be induced to resume the subject. 



In 1801, Lord Dundas, then Governor of the Forth and 

 Clyde Canal Company, employed Mr Symington to make an 

 engine for an experimental vessel for that company. The 

 vessel was soon after completed, and made many experimental 

 trips on the canal, — but being found to create a wave destruc- 

 tive to the banks, was on that account laid aside. 



It was this latter vessel (the third in succession from the 

 first trial), which was visited and studied by Mr Fulton, the 

 American engineer, Avhose first steam-boat was launched in 

 1807, nineteen years after the successful trial on Dalswinton 

 Lake. Mr Henry Bell of Helensburgh, who constructed the 

 steam-boat " Comet," on the river Clyde in 1812, accom- 

 panied Mr Fulton in his visits to Lord Dundas's vessel. 



The above noted facts are supported by vouchers from va- 

 rious persons, several of whom are still alive, and are fully 

 coiToborated. b}- accounts published in the Dumfries .Journal 

 and the Scots Magazine of 1788, and in the Edinburgh ncAvs- 

 papers of February 1790. — I remain. Sir, your very obedient 

 Servant, John Robison. 



James Tod, Esq. Sec. Soc. of Arts. 



It is not generally known that the engines fitted in Fulton's 

 first steamer, on the Hudson, were furnished by Messrs Boul- 

 ton. Watt, and Co. of Soho, who were applied to by Mr Fulton, 

 in person, to undertake to construct them. 



On the Habits of Testaceous Mollusca belonging to the genera 

 Achatina and Phasianella. By F. Logax, Esq., Surgeon, 

 R. N. Communicated by the Author. 

 Thi; following facts and observations, collected from notes 

 taken at the Isles de Loss and Rio Nunios in 1830, relate 

 to some natural i)henomena seen in two species of testace- 

 ous mollusca, belonging to the genus Achatina, and in another 

 belonging to the genu.'? Phasianella, The Isles de Loss, about 



