on St. John's began in early 1893. The trustees initially expected that work would proceed quickly because much of the Morningside Heights plateau was made of shallow bedrock. However, in September 1893, builders unexpectedly hit pockets of soft shale and an underground spring at several locations about below ground. One of these pockets was located directly below the site for one of the four piers that were to support the cathedral's massive stone tower. The trustees briefly considered moving the entire cathedral slightly southward. They ultimately decided against moving the cathedral, believing it to be inauspicious if the cornerstone were to be moved. Instead, builders drilled several deep shafts until they hit the bedrock, then poured concrete pits within each shaft. The pits would then accommodate the construction of the tower's piers. The layer of bedrock was, in some cases, beneath ground level. The pits were completed in late 1895 at a significantly higher cost than originally estimated. By 1898, St. John's had cost an estimated $750,000, and as per an 1896 estimate, the cathedral was projected to cost at least $5 million when complete. As a temporary measure, the Tiffany Chapel was purchased in mid-1898 so that services could be held there. The chapel was placed in the crypt, within the basement. The first services were held in January 1899 within the Tiffany Chapel. The crossing arches, located in the cathedral plot's eastern portion, were completed the following year, though three of the arches were temporarily sealed off until the transepts and nave could be completed. By then, some $2 million had already been spent, even though little appeared to have been completed. Despite large donations from prominent figures such as financiers John Jacob Astor IV and William Waldorf Astor, governor Levi P. Morton, banker J. P. Morgan, and businessman Cornelius Vanderbilt, the trustees continued to raise funds. In March 1903, the trustees announced that the next stage of St. John's construction would require $500,000 for building the choir and $200,000 for completing the loft, and that eight massive granite columns would need to be procured to support the roof over the choir. Furthermore, the trustees would build three arches to support the rest of the roof. The choir columns, sourced from Vinalhaven, Maine, were each tall with a diameter. At the time, they were the world's second-largest stone columns, but because of their size, three of the columns