similar system was introduced at Wesleyan University in nearby Middletown, Connecticut, but with a pair of societies in each class year and dual memberships between class societies and college fraternities, so that most class society members were also fraternity members. The older societies survived because of their endowments, real estate, and the vigor of their respective alumni organizations and their charitable Trusts. In the past century, the size of Yale has allowed for a wider variety of student societies, including regular college fraternity chapters, and other models, so it can be challenging to categorize the organizations. And there are societies like Sage and Chalice, Brothers in Unity, and St. Anthony Hall which cross ordinary categories. There are typical attributes of the Yale societies. They are often restricted by class year, especially the senior class. They usually have fifteen members per class year. They "tap" their members, mostly on the same "Tap Night", and a member is off-limits to recruitment by another secret society, (i.e. reciprocal exclusivity). The normal pattern now is that a group of secret societies places an advertisement in the Yale Daily News in early spring that informs students when Tap Night is taking place and when students should expect to receive formal offers (usually one week before official Tap Night). Tap Night is typically held on a Thursday in mid-April; the most recently held Tap Night was on April 10, 2014. During 1854–1956, "'Sheff, the Sheffield Scientific School was the sciences and engineering college of Yale University, and it also had a fraternal culture that differed in some respects from the humanities campus. Many societies have owned meeting halls, with different accommodations. Following the example of Skull & Bones, the halls are often referred to as 'tombs'. A series of articles on Dartmouth and Yale secret-society architecture provides an overview of the buildings. Societies that own tombs or halls are sometimes known as 'landed' societies. The four oldest landed societies are Skull and Bones (1832), Scroll and Key (1841), Spade and Grave (1864), and Wolf's Head (1883). The surviving landed Sheffield societies are Berzelius (1848), Book and Snake (1863), St. Elmo (1889), and the Aurelian Honor Society (1910). St. Anthony Hall (1867) calls itself a "final society". Three newer societies that own property include Elihu (1903) – whose building is the oldest of the senior society buildings at Yale – Manuscript Society (1952), and Mace and Chain