From an account of some new ordnance made in 1671, we find that iron cannon of 7 were 10 feet long, and weighed on an average 63 cwt., or 9½ feet long, and weighing from 54 cwt. to 60 cwts. Iron culverings of 10 feet in length averaged 43 cwt. in weight, and demi-culverings of the same length averaged in weight about 35 cwt. Iron falconetts are mentioned 4 feet in length, and weighing from 300 to 312 lbs. The King, having occasion to send a present to the Emperor of Morocco, not an unfrequent occurrence, selected on one occasion four iron demi- culverings, and three brass demi-cannon of 8½ feet long, with one brass culvering of 11½ feet. A more frequent present to that monarch was gunpowder, or a quantity of muskets. The salutes in the Tower were fired from culverings and 8-pounders, and were in a very special manner under the command of the Master-General himself. As little liberty of thought was left to the subordinates at the Tower as possible. Warnings of preparation were forwarded often days before, followed at intervals by reminders that the salute was not to be fired until a positive order should reach the Tower from the Master- General. The letter-books at the Tower teem with correspondence and orders on this subject, and the Master-General seemed to write as many letters to his loving friends at the Tower about a birthday salute, about which no mistake could well occur, as he did about a salute of another kind, albeit a birthday one, when on the 10th June, 1688, "it pleased Almighty God, about ten o'clock of the morning, to bless his Majesty and his Royal Consort, the Queen, with the birth of a hopefull son, and his Majesty's kingdom and dominions with a Prince: for which inestimable blessing" public rejoicing was invited. It was a false tale which the guns rang out from the Tower:—only a few months, and the hopeful babe was a fugitive with its ill-fated father, and remained an exile for his life. "He was indeed the most unfortunate of Princes, destined to seventy- seven years of exile and wandering, of vain projects, of honours more galling than insults, and hopes such as make the heart sick."[6] At this time, Woolwich was gradually increasing in importance as an Artillery Depôt, and in 1672 the beginning of the Laboratory was laid, 70 feet long, "for receiving fireworks."