Barrack Bridge was originally constructed of wood, and was erected in 1670; and its popular name of Bloody Bridge was derived, as Harris the historian states, from the following circumstance, which occurred in the year after. The apprentices of Dublin having assembled themselves riotously together with an intention to break down the bridge, it became necessary to call out the military to defeat their object, when twenty of the rioters were seized, and committed to the Castle. It happened, however, afterwards, that as a guard of soldiers were conveying these young men to the Bridewell, they were rescued by their fellows, and in the fray four of them were slain; “from which accident it took the name of Bloody Bridge.” In a short time afterwards, this wooden structure gave place to the stone bridge we now see, which is of unadorned character, and consists of four semicircular arches. Its rude and antique appearance, however, harmonizes well with the military gateway placed at its south-western extremity, on the road leading to the Royal Hospital at Kilmainham. This gateway, which was designed by the late eminent architect, Francis Johnston, Esq. P.R.H.A., and erected for government, under his superintendence, in 1811, consists of a square tower, having smaller square towers projecting from three of its angles, and a circular one of greater diameter and altitude at its fourth or north-eastern angle. The object for which this gateway tower was erected, as well as the period of its erection, is indicated by escutcheons on its east and west sides, bearing the arms of the Duke of Richmond and the Earl of Harrington, the lord-lieutenant and the commander of the forces of the time. A similar shield on its north side facing the river, sculptured with the armorial bearings of the family of Johnston, indicates the name of its architect; and it is worthy of mention as a characteristic of the love for posthumous fame of Mr Johnston, that this tablet was not known to exist till within a few years back, and after he had himself paid the debt of nature; having been concealed from view by a box of wood fastened against it, and which was suffered to remain--a strange mystery to the curious observer--till it fell off from decay. P. ON THE IMPORTANCE OF ATTENDING TO THE QUALITIES OF SEED, AND THE CONDITION OF THE SOIL, IN THE SOWING SEASON. BY MARTIN DOYLE.