These crawls are part of an effort to archive pages as they are created and archive the pages that they refer to. That way, as the pages that are referenced are changed or taken from the web, a link to the version that was live when the page was written will be preserved.
Then the Internet Archive hopes that references to these archived pages will be put in place of a link that would be otherwise be broken, or a companion link to allow people to see what was originally intended by a page's authors.
This is a collection of web page captures from links added to, or changed on, Wikipedia pages. The idea is to bring a reliability to Wikipedia outlinks so that if the pages referenced by Wikipedia articles are changed, or go away, a reader can permanently find what was originally referred to.
Newly constructed global indices of ocean freight rates in the 1850s show large cyclical fluctuations in these years. A new type of freight rate index, referred to as a repeat sailings index, is presented, which is similar to a type of index frequently applied to house prices. An econometric model of the freight rate market is estimated on monthly data from the 1850s. It is found that harvest failures, business cycles, the supply of tonnage and the Crimean War all significantly affected freight rates in this period. The Crimean War may have accounted for about a quarter of the surge in freight rates in the years prior to the outbreak of the War; once the War broke out in March 1854, however, it was of less importance.