IT is a fact not generally known, that it was in Glasgow Green, near the site of the Humane Society House, that the idea of his great improvement on the steam-engine first flashed on the mind of our immortal James Watt.

The great engineer was at that period philosophical instrument maker to the University. In this capacity a small working model of Newcomen’s atmospheric engine was sent to him for repair by Professor Anderson. While the machine was still in his possession for this purpose, he went out alone, on a Sunday afternoon, to take his customary walk on the Green.

His mind was naturally enough directed to the contemplation of the principles upon which the engine he had been repairing was constructed, and just as he was passing Arn’s Well, the happy thought struck him, that by condensing the steam in a separate vessel instead of in the cylinder, as it had hitherto been done, an immense saving of fuel would be effected.

Had Watt been an ancient Greek he would probably, on such an occasion, have rushed across the Green, shouting "Eureka! Eureka!" But canny Scot as he was, and probably in wholesome dread of the kirk session, he pursued his leisurely thoughtful walk, and (according to his own account of the matter, as related to a highly respectable gentleman of this city), he fully mastered the details of his great discovery before returning home.

Immediately thereafter, in concert with his apprentice, Mr. John Gardner, who was subsequently for many years a mathematical instrurnent maker in this city, he constructed a model of the steam-emgine according to his new and improved method. This wrought admirably. The first experiment on a large scale took place at a coal mine near the Carron ironworks, when his expectations were fully justified, and he was induced to take out a patent for "saving steam and fuel in fire-engines."