Ixxvi Proceedings of Royal Society of Edinburgh. 
Paraffin is now almost universally used in lighthouses. At present 
prices, and at the present rate of consumption, the use of paraffin 
in British lighthouses alone results in a yearly saving of between 
^35,000 to £40,000. 
His firm’s practice as lighthouse engineers was not confined to 
the Scottish Board, as their advice was taken by the Governments 
of India, China, Newfoundland, New Zealand, Japan, and other 
foreign governments, and schemes for the lighting of the whole 
coasts of the two last named countries were devised and are now 
being carried out. In his book on Lighthouse Construction and: 
Illumination, the results of the practice of his firm in lighthouse 
construction and optics are given. For some of his inventions laid 
before the Royal Scottish Society of Arts, Mr Stevenson was 
awarded gold medals ; but it is perhaps proper to say that for none 
of his inventions has he, or any member of the Stevenson family, 
taken out patents, all lighthouse authorities having had free use of 
their designs and improvements in dioptric apparatus and lighthouso 
economy generally. 
Perhaps I may be allowed to quote the testimony of Captain 
Sulivan, the professional adviser of the Board of Trade, when in 
1861, giving evidence before the Royal Commission on Lighthouses,, 
he stated: — “ It is to Mr Stevenson we owe the present state of our 
lighthouse illumination — for the improvements on the Fresnel light 
which he has made have really given us the superior class of lights 
that we have now in England. All that has been done, that I 
can see, to improve on the system, and to give us a better class of 
dioptric light, has been done by Messrs Stevenson, and I believe 
that that is quite the feeling of every one at the Board of Trade.” 
The practice of the firm, of which Mr Thomas Stevenson was a 
member, was not confined to lighthouse engineering, as they v/ere 
mainly engaged in the construction of harbours, docks, and river 
and estuary improvements. With most rivers and harbours in 
Scotland he and his partners were in some way professionally con- 
nected, while they were also called upon to design works for the 
improvement of harbours, and of many rivers and estuaries in 
England and Ireland. To the subject of harbour construction Mr 
Stevenson directed his attention, bestowing special care in ascer- 
taining the forces which have to be met and overcome in the 
