1. You should have located your item through the catalog and found the record.
2. Here's a library book location map.
3. After you've gone to the floor where your book is located...follow the stacks around the floor by reading the letters and numbers on each end cap. These are part of the the library of congress classification system.
This plaque will be found at the end of each section of shelving, the range of call numbers on the left side is for books on that side of the book shelf. The call number DA 772 .R72 1884 1971r v.1 falls between the two call numbers below. The 772 in the call number is between 670 and 1051, the numbers will be in numerical order on the shelf from left to right and top to bottom, when you see books in the 700's you'll know your close. There may be multipule books with 772 in the call number within the DA section, the third set (e.g. .R72) with further narrow down the books location.
4. Locate your book within the stacks by reading the call number.