Crime in London was rare. Murder, burglary, highway robbery, and gross theft were punishable by hanging. Forgery, fraud, was punishable by the placement in the pillory or stocks or by imprisonment. Perjury was punished by confession from a high stool for the first offense, and the pillory for the second. Slander and telling lies were punished by the pillory and wearing a whetstone around one's neck. There was an ordinance passed against prostitutes in 1351. London as well as other port towns had not only prostitutes, but syphillus. Prominent Londoners sought to elevate their social position by having their family marry into rural landholders of position. For poor boys with talent, the main routes for advancement were the church, the law, and positions in great households. Many master freemasons, who carved freestone or finely grained sandstone and limestone artistically with mallet and chisel, left the country for better wages after their wages were fixed by statute. The curvilinear gothic style of architecture was replaced by the perpendicular style, which was simpler and cheaper to build. Church steeples now had clocks on them with dials and hands to supplement the church bell ringing on the hour. Alabaster was often used for sepulchral monuments instead of metal or stone. With it, closer portraiture could be achieved. In the 1300s and 1400s the London population suffered from tuberculosis, typhus, influenza, leprosy, dysentery, smallpox, diphtheria, measles, heart disease, fevers, coughs, cramps, catarrhs and cataracts, scabs, boils, tumors, and "burning agues". There were also many deaths by fires, burning by candles near straw beds when drunk, falling downstairs when drunk, and drowning in the river or wells. Children were often crushed by carts, trampled by horses, or mauled by pigs. Towns recognized surgery as a livelihood subject to admission and oath to serve the social good. Master surgeons were admitted to practice in 1369 in London in full husting before the mayor and the aldermen and swore to: faithfully serve the people in undertaking their cures, take reasonably from them, faithfully follow their calling, present to the said mayor and aldermen the defaults of others undertaking, so often as should be necessary; to be ready, at all times when they should be warned, to attend the maimed or wounded and others, to give truthful information to the officers of the city as to such maimed, wounded, or others whether they be in peril of death or not, and to faithfully do all other things touching their calling. Some young girls of good families were boarded at nunneries to be taught there. Some upper class widows retired there. Only women were allowed to be present at a birth, at which they spread the knowledge of midwifery. As usual, many women died giving birth. Various ways to prevent pregnancy were tried. It was believed that a baby grew from a seed of the father planted in the woman's body.