Barrie Hedge is a volunteer in the LuEsther T. Mertz Library of the New York Botanical Garden.

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My decision to become a volunteer several years ago was made because of the significant impact the New York Botanical Garden had on my life. I studied Landscape Design through the NYBG Landscape Design Certificate Program and became a qualified Landscape Designer after many years in the advertising world. Over 15 incredibly fulfilling years I completed several hundred landscaping projects, mostly complete renovations. Volunteering at NYBG seemed like the perfect way to express my gratitude and give back.  

I was placed at the LuEsther T. Mertz Library. Established in 1899, this remarkable collection spans over 800 years of scientific research. When I arrived, I was tasked with conducting an inventory of the lantern slide collection; this collection holds over 14,000 slides spanning between the 1840s to 1930s. After three years of consistent commitment to this inventory, I have completed it.  

Upon casual viewing it could easily be mistaken as a random assortment of photographs, but once you spend time with the collection you begin to realize they tell a story. For example, a cluster of 15 images of orchids, or perhaps a cluster of trees and plants damaged by diseases, maybe another cluster of landscapes of Haiti—and it suddenly clicks that these were all curated presentations on those subjects!  

The development of the lantern slide collection at the Mertz Library happened gradually over the period between the late 1890s to the late 1930s, including both hand-colored and uncolored slides. The collection was primarily used for the Garden’s long-standing Saturday Afternoon Public Lectures as well as research and publication. A bit over 5,700 slides were created after NYBG led botanical expeditions. Elizabeth G. Britton, Percy Wilson, and later Forman T. McLean oversaw the lantern slide collection and described the collection’s contents, use, and growth in their reports in the Bulletin.  

So, what exactly is a lantern slide? Lantern slides are glass slides that were created to project images using a magic lantern device. The Mertz library’s collection is made up of hand-colored photographic images on 4” X 3¼” glass slides. They are extremely delicate, and you need to be very careful when handling them. Occasionally I came across a slide that had been damaged, but the vast majority remain in excellent shape.

During this inventory, I personally found that one of the most interesting and compelling collections was done by a famous New Zealand botanist, Leonard Cockayne. The images were taken in the very early 1900s; some we know were taken in 1901.  

The slides feature landscapes, waterfalls, and mountains in New Zealand, and the botanical slides are especially fascinating because, given the location, some are quite different and unusual plant species which people may not be as familiar with here in New York. Particularly striking are a series of slides that refer to plants from Chatham Island (for example, Chatham Island Palm and Chatham Island Asters). Chatham Island is extremely remote, being 500 miles east of New Zealand. Cockayne made an expedition to Chatham in 1901 to look at and investigate the plant material, finding that much of it is endemic to Chatham. In 1902, Cockayne published his findings in A short account of the plant-covering of Chatham Island —of which the Mertz Library holds a copy!  

I completed the inventory of the slides on November 4, 2025. The last slide inventoried was taken in Ontario, Canada, in a woodland area in Marmora province near Prince Edward Island. It is of two pale green orchids scientifically known as Habenaria flava. It is not one of the most compelling slides in the collections, but is very much a part of the story this collection shares. Now we know that there are 14,110 lantern slides waiting to be viewed, waiting to be admired as they have already been in the past. Now that they have been inventoried, we know exactly what is in the collection!