Featured below are a variety of wonderful examples of Large Format (Lantern Slide) whole insect mounts made by the firm of Carpenter & Westley, London; probably circa 1850s. Each of these Lantern Slides was constructed using an approximately 3" diameter double glass slide component, mounted in a 3 3/4" x 6 7/8" solid mahogany frame piece. These were originally produced for use with their Solar or Oxy-Hydrogen Microscopes, as well as various other "Magic Lantern" type models. Philip Carpenter (1776-1833), founder of the company that eventually became Carpenter & Westley in 1835, invented his Phantasmagoria Lantern in 1821, and the "Improved" Solar Microscope in 1826. An interesting look at the life of Mr. Philip Carpenter, including his wonderful contributions and discoveries can be found here.

These Large Format Slides are amazing examples of the insect mounters art. The difficulty in successfully preparing and mounting large or multiple insects in Canada balsam, with few, if any air inclusions or severe displacements, would have required a very high degree of specialist skill. My own comparisons to standard sized (3" x 1") microscopical insect mounts from known preparers of that time, suggest that these large format slides may have been made by one of those professional mounters (** See Below). The quality is comparable to only the most capable mounters of the era.  In any event, they are wondrous examples of the whole insect mounters art! A standard 3" x 1" mount is shown below for size comparison.

** Some recent research has uncovered a most interesting bit of information, directly related to the creation of Large Format whole insect mounts by Carpenter & Westley. It appears that some of the first successful efforts to use Canada balsam in the mounting of microscopical specimens, possibly circa early to mid 1830s, were perfected by a Mr. New in the employ of Mr. Carpenter, and Mr. (J.W.) Bond who was an early commercial mounter. Both of their efforts seem to have been initially directed towards mounting of large format whole insect specimens for public display using the Solar and Oxy-Hydrogen Microscopes of the day.  Mr. Bond went on to provide mounted specimens to the Adelaide Gallery, and also mounted small and standard sized microscopical preparations for many years. This very interesting story is from  the reminisces of J.S. Bowerbank in a paper read before the Royal Microscopical Society in 1870. Excerpted relevant pages can be found here.

Shown above, a close-up, and below a photomicrograph (using DIC), taken from the slide of "Earwigs". The mount quality is quite evident. The higher magnification views seen through a microscope are generally comparable to those seen when examining some of the finest standard 3" x 1" size whole insect mounts from the same era.
Here, a  beautifully mounted pair "Male & Female, Smoked Wing Dragonfly", with whole slide shown above, and close-up view below.,

Below, a fine mount of a "Red Admiral" butterfly, and an artistically presented pair of "Aphona" beetles; whole slides

Detail above, with whole slide shown below; a somewhat breathtaking mount of "Centipede".

Above, a close-up of an amazing mount titled "Small Tortoise Shell Butterfly" showing 3 stages of development; caterpillar, chrysalis, and an adult butterfly. And below, the whole slide. 

Below, 2 species of moths; a "Tiger Moth" with detail and whole slide shown, and the "Emperor Moth", detail bottom

And lastly, an interesting and fascinating multiple whole mount titled simply "Scorpions"