Eye chart smaller symbols until the person cannot identify the symbols. The smallest symbols that can be reliably identified is considered the person's visual acuity. The Snellen chart is the most widely used. Alternative types of eye charts include the logMAR chart, Landolt C, E chart, Lea test, Golovin–Sivtsev table, the Rosenbaum chart, and the Jaeger chart. Charts display several rows of optotypes, which are standardized symbols for testing vision. Optotypes are usually letters, numbers, or geometric symbols. Each row of the chart depicts optotypes of a different size. Typically the largest optotypes are in the top row. The optotypes become progressively
Letter-Books of the City of London Letter-Books of the City of London The Letter-Books of the City of London are a series of fifty folio volumes in vellum containing entries of the matters of in which the City of London was interested or concerned, beginning in 1275 and concluding in 1509. The volumes are part of the collection of the City of London Records Office, and are kept in the London Metropolitan Archives. The volumes derive their name from being lettered from "A" to "Z" (with two odd volumes marked respectively "&c." and "AB") and again from "AA" to "ZZ". Besides being known by distinctive letters,