The collection was formed by the mathematician John Sturgeon Mackay (1843-1914), MA, LLD (St Andrews) FRSE (1882), mathematical master at Edinburgh Academy and presented in his memory by his brother Robert Mackay in 1923. It contains in 52 volumes mathematical works of the 16th-19th centuries. All but 7 items are pre-1851, 36 are pre-1801. It is strong in Euclid items (19) in various languages - mostly separate editions of the Elementa, including the first Greek edition (Basle, 1533) and the first Arabic edition (Rome, 1594).
The Mackay collection is entirely accessible via the online catalogue. Classmarks for books in this collection have the prefix Mac and can be found here.
There is a libguide for the Mackay collection on the University of St Andrews Library libguide site. Libguides are sets of web pages for research assistance, subject guides, and useful resources compiled by librarians.