This month’s featured object is a Gunter scale, sometimes referred to simply as a Gunter. Invented in 1623 by English mathematician and astronomer Edmund Gunter, the Gunter scale was used to solve various mathematical problems through the use of logarithms and is essentially an early version of the slide rule. It had multiple scales engraved on both sides of its wooden surface, and it incorporated tiny brass inserts which were used to orient the points of a pair of compasses that were used to transfer measurements from one scale to another. Most Gunter scales were about two feet long though smaller ones were made, the one pictured here is only about a foot long, and possibly is one half of a full sized scale.The Gunter scale was also used by sailors as a navigational aid, and was a standard piece of equipment for the British navy into the mid-nineteenth century. In conjunction with charts, the scale was used to plot course lines through the use of logarithms.
Which member of the Longfellow family this piece belonged to is unclear, but a good bet is that it was owned by Alexander Wadsworth Longfellow, Sr., younger brother of the poet Henry Wadsworth Longfellow. Alexander studied civil engineering in college, and from the 1840s until the 1860s worked for the U.S. Coast Survey (now called the National Oceanic and Atmospheric Administration), mapping coastlines along the eastern seaboard from Maine to Virginia. An item such as this Gunter scale would have proven valuable to his work.