Libraries demand precision, consistency, accuracy. Take a book, pull it from its designated place, stick it where it doesn't belong (we've all seen patron's do this) and it's lost. We assign numbers to books so they will go in a precise location. Each number represents a specific subject, author, creator, date of publication, and may be completely inappropriate for the subject of the book. This does not matter. What matters is the placement of the book according to the number. If the book says it's in a specific place, and it's not, it's lost.
While camping at Emerald Bay I came upon something I had never before seen. I "found" a U.S. Coast and Geodetic Survey mark. It was anchored firmly in a rock overlooking Lake Tahoe.
Over the last 202 years the Geodetic Survey planted over 1,200,000 marks throughout the U. S. and it's possessions. Now they use bronze and brass disks. They had used jars and bottles, church steeples and water towers. Now they set disks in rocks, concrete pillars and other "monuments."
These marks are used to determine precise geographical locations: latitude, longitude, elevation. While most of us could not articulate why surveys are needed we can exclaim the usefulness of a GPS (global positioning system). For those directionally challenged a GPS saves embarrassment. A GPS would not be possible without the precise work of the U. S. Coast and Geodetic Survey over the last 202 years.
Gerald F. Ward