After the Union the unequal incidence of the duties leviable for the light of May--English and Irish vessels being charged double rates as foreigners--gave rise to much dissatisfaction. In addition to this, there was a general feeling that anything that was payable in the form of a tax ought not to be held as private property. With regard to the light itself, it gradually became more evident that a coal fire, exposed in an open choffer to the vicissitudes of the weather, was altogether inadequate to the requirements of the shipping trade. After the appointment of a Lighthouse Board in Scotland in the year 1786, those most directly affected often expressed a wish that the light of May should be included as one of the Northern Lights; that it should get the benefit of the most recent improvements; that, in accordance with the spirit and conditions of the Act for the regulation of the Northern Lighthouses, the invidious distinction between the shipping of the three kingdoms should be done away with; and, further, that there should be some prospect of the duties being modified and ultimately ceasing altogether. Moved by these various considerations, the shipping trade of the Firth of Forth repeatedly approached the family of Scotstarvit, into whose hands the property and light of May had come by purchase, in 1714, with a view to the improvement of the old beacon. In consequence of representations from the Chamber of Commerce of Edinburgh, which visited the island in 1786, the choffer was enlarged to the capacity of a square of three feet, and the quantity of fuel annually consumed increased to about 400 tons. The Chamber further recommended that the stock of coals, hitherto exposed to the open air on the island, should in future be kept under cover, and that the supply should invariably be obtained from the collieries of Wemyss, of which the coal was considered fittest for maintaining a steady light, and was consequently employed at Heligoland and other coal lights on the Continent. All these conditions were complied with by Miss Scott of Scotstarvit's tutors, and from that time the May beacon became the most powerful coal light in the kingdom, the capacity of its choffer being double that of any other. But even these improvements could not prevent it from being unsteady in bad weather, and there still remained the great disadvantage that limekilns and other accidental open fires upon the neighbouring coast were apt to be mistaken for the May light. To obviate the possibility of such mistakes, the Trinity House of Leith, in 1790, presented a memorial to the Duke of Portland, who, through his marriage with Miss Scott, had become proprietor of the May, and requested him to replace the coal-beacon by an oil-light with reflectors, enclosed in a glazed light-room. In spite of this application and of many others from various quarters, no further improvements were introduced at the time.