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and actual trial during a month at Girdleness Lighthouse, a report 
was made to the Northern Lighthouse Board, embodying the follow- 
ing results: — That paraffin, as now manufactured, with a high specific 
gravity and flashing point, is safe ; that the flame is of great purity 
and intensity, and easily maintained ; the lamp glasses and lamps 
used for colza are equally suitable for paraffin ; and that the initial 
power of the lights on the Scottish coasts would be exalted, and 
this, too, at an annual saving of £3500. The relative merits of 
colza oil and paraffin were thus settled, and most British and 
many European, foreign, and colonial lighthouses now consume 
paraffin, with an increased luminous intensity, and decreased cost 
of maintenance. 
Mr Stevenson frequently appeared before Parliamentary Com- 
mittees, and also gave evidence before Special Committees and 
Royal Commissions on Harbours, River Improvements, Harbours of 
Refuge and Lighthouses. For these Committees and Commissions 
he always prepared with scrupulous care ; and he was a most con- 
scientious witness, never entering the box without being satisfied 
as to the soundness of the cause he was supporting ; and in no case 
did a Committee ever throw out a Bill, the Parliamentary plans 
and estimates of which he had prepared. In his native city Mr 
Stevenson was greatly respected, and his advice on many important 
matters connected with city improvements was sought and highly 
valued. His views on the city improvement scheme, as conveyed 
to Lord Provost Chambers and the late Mr David Cousin, city 
architect, along with his letters which appeared in the Scotsman at 
the time, greatly facilitated the initiation of this great sanitary im- 
provement, now nearing its completion. Among other local works, 
his firm designed and carried out the Edinburgh and Leith and 
North Leith sewerage schemes, and the widening of the North 
Bridge. 
Mr Stevenson was consulting engineer to the Convention of 
Royal Burghs of Scotland and to the Highland and Agricultural 
Society. In the affairs of the latter he took a lively interest, 
especially in the trials of improved agricultural implements; and be 
contributed several papers and reports to their Transactions , notably 
one on the reclamation of land, and one on the relative merits of 
different systems of steam ploughing. The paper on “Reclamation 
