PROSPEROUS, a town, in the parish of KILLYBEGGS, barony of CLANE, county of KILDARE, and province of LEINSTER, 11 miles (S. W.) from Leixlip; containing 1038 inhabitants.

This place, which is situated near the Grand Canal, owes its origin to Mr. Robert Brooke, who, towards the close of the last century, expended a large fortune in attempting to establish the cotton manufacture here. In less than three years a town, consisting of 200 houses, was built, and establishments were completed for all the various branches of that manufacture, including the printing of linen and cotton goods, and also for making the requisite machinery connected with the works; and from the flattering prospect of success which grew with the attempt, the town rather prematurely derived its name.

In pursuing this object, however, that gentleman exceeded the limits of his own private fortune, and upon application to parliament obtained a grant of £25,000; but in 1786, having again occasion to apply to parliament for assistance, his petition was rejected and the works consequently were discontinued.

Upon this occasion 1400 looms were thrown out of employment, and every other branch of the manufacture, together with the making of the requisite machinery, ceased. Though the undertaking was never revived, still the manufacture was continued on a very limited scale till 1798, when, during the disturbances of that year, a party of the insurgents attacked the town and surprised a party of the king's troops, whom they put to the sword.

Since that period the town has gradually declined in importance, and is at present little more than a pile of ruins; a very few weavers still find some employment, but its situation in a low and marshy spot, surrounded by bogs and without water-power, affords neither advantages for the establishment of works of importance, nor reasonable hope of its revival.

Near the town, the Grand Canal is carried through the hill of Downings. A constabulary police station has been established here, and there is a small thatched R. C. chapel.