The Blaschka glass models

Who were the Blaschkas?

Rudolph Blaschka (left) and Leopold Blaschka (right)

Leopold (1822-1895) and Rudolf (1857-1939) Blaschka were a father and son partnership, originally from Bohemia. Their work making spectacular glass models of natural history objects began in 1857, in Germany. Rudolf joined his father in business in 1876 and after 1880 there were so many orders for their glass models that this became their sole business.

The Blaschkas are best known for their glass flowers, made from 1886 to 1936. Many of these are now displayed in the Botanical Museum of Harvard University. After his father's death in 1895, Rudolf continued to make glass flowers. 

During their lifetimes, the Blaschkas also made many accurate models of marine animals. They died with no children, so their glass-working secrets were not passed on.

Each glass model is a unique blend of art, science and craftsmanship that excites and inspires everybody who sees it.

The inspiration

Another radiolarian glass model

Ideas for many of the models can be traced directly to illustrations in scientific books of the day. Some of the models made after 1880 were based on animals kept in the Blaschkas' own salt water aquarium.  Some were also prompted by the sketches of Rudolf Blaschka when he was marooned off the Azores during a trip to the USA, just after his father's death.

Two scientists were known to have greatly influenced the Blaschkas. Many of their early sea anemone models were based on Goss (1860) and models of many of the marine animals they made, including the Museum's radiolarian models, were based on the studies of Haeckel, particularly his monograph of 1862.

How they were made

Glass model of a squid

The models vary greatly in the way they were made. Many are formed over wire skeletons known as armatures, with the glass fused together or glued. This involved a process called lampworking. The glass is melted over a torch or flame until it becomes soft and malleable and then pulled or twisted into shape with various tools.

Models made between 1886 and 1895 were made of clear glass and cold-painted with things like fish glue from sturgeon, dammar (botanical sap), hide glue and gum Arabic. Later models were often enamelled. Other materials used to make the models included painted paper for internal structures and actual shells of terrestrial, freshwater and marine gastropods (snails etc).

Arrival at the Museum

The radiolarian model before conservation

The Natural History Museum holds 187 Blaschka models of marine invertebrates such as sea anemones, nudibranchs, octopi, squid, jellyfish, radiolarians, amoebas, corals and echinoderms.  The models arrived at the Museum in 1866, 1876, 1883 and 1889, and span almost the entire time that the Blashckas were making models of marine invertebrates.

Conservation

Pollution damage, metal corrosion, salt migration and poor storage have made the models very fragile. Many of the original lacquers and glues are highly soluble, making the specimens difficult to clean and conserve. All of them have now been re-boxed. 

A Museum conservator working on the radiolarian model

All of the jellyfish models and some of the radiolarians, including the specimen on display in The Deep exhibition, have been cleaned by conservators from the Museum's Palaeontology Conservation Unit.

The models have been analysed using modern techniques, including CT and surface laser scanning, FTIR (Fourier-Transform Infrared microscopy), Raman spectroscopy, microprobe (EDX) and SEM (Scanning Electron microscopy).  This has given further information on how they were built. It helps the conservators to understand the deterioration processes better and to improve their conservation methods.