Darwin the Geologist, Sedgwick Museum of Earth Sciences, Cambridge; A Voyage Round the World, Cambridge University Library

Cambridge has been paying homage to one of its most famous alumni throughout 2009, with exhibitions and events to celebrate the bicentenary of the birth of Charles Darwin and the 150th anniversary of the publication of On the Origin of Species.

The Sedgwick Museum of Earth Sciences and Cambridge University Library are playing to the strengths of their respective collections by holding exhibitions examining the formative years of the naturalist, decades before the publication of that world-changing book.

Although Darwin the Geologist is ostensibly "a story about rocks", it is also an insight into the mind of a man fascinated by the natural world. The Sedgwick's new permanent exhibition reveals how Darwin's lifelong passion for geology acted as the foundation for his later theories of evolution. His collection of rocks and fossils from the Beagle voyage made his reputation as a scientist.

Many specimens are displayed here alongside contextual artefacts such as scientific instruments and old containers. Darwin recycled barrels, sauce bottles and pill boxes to store specimens and ship them back to England for identification.

His handwritten notes still lie crumpled protectively around some of the stones. He used a meticulous system of notebooks and colour-coded labels to catalogue his collection, a method reminiscent of that used by Josiah Wedgwood for storing thousands of pottery samples.

There is a thread of continuity here because the two families were related through marriage and Josiah II (the politician son of the famous potter) was Darwin's uncle and the man responsible for persuading Darwin's father to support Charles on the Beagle's voyage of discovery.

Unattached, keen and affable

Meanwhile, Cambridge University Library has a show that aptly describes the Beagle voyage as "the most significant gap year in history". A Voyage Round the World examines this pivotal event through manuscripts, letters, maps and herbarium sheets, as well as a selection of evocative sketches and watercolours by the Beagle's artist, Conrad Martens.

We learn that the 22-year-old Darwin earned his place on board the ship largely as a result of being unattached, keen and affable. Among the exhibits is a letter of recommendation from his tutor, JS Henslow: "I assure you I think you are the very man they are in search of."

There is also the letter from Josiah Wedgwood II to Darwin's father, written in support of the trip: "...looking upon [Charles] as a man of enlarged curiosity, it affords him such an opportunity of seeing men and things as happens to few."

The choice of artefacts gives a sense of what it meant to take part in the voyage and, more poignantly, of history in the making. Letters were an important way for Charles to obtain guidance from some of the leading scientists of the day as well as providing eagerly awaited news from home as the two-year voyage increased to almost five years. Darwin left England an untried Cambridge graduate and returned as a leading light of the British scientific community.

Both displays are modest in size but rich in content, and both are located within the confines of a pre-existing space with relatively inflexible configurations of showcases and lights. Neither uses techniques that are particularly unique or unusual, yet they both place artefacts and careful interpretation at the heart of the visitor experience.

Whereas the library caters for a well-educated adult audience in an effort to tempt readers away from their books for a well-earned break, the Sedgwick deploys interactives and programming to attract a wider, family-based audience.

Its new display is part of a long-term project to modernise interpretation throughout the museum in an attempt to make it more accessible and to broaden its visitor base. Although the library doesn't use interactives, its show is accompanied by an exquisite catalogue, which complements the graphic panels.

Down House medal

The Sedgwick has a listed interior that can only be altered in a non-permanent way. Wooden showcases have been cleverly adapted to incorporate pullout drawers, space for a computer terminal and an interactive globe with a projection of the voyage.

The original showcases present a challenge for curators striving to meet modern loan conditions. A medal borrowed from Down House is displayed inside a miniature lockable casket housed within a larger showcase; a discrete solution that meets security requirements while managing not to detract from the aesthetics of the overall display.

There was one small annoyance. Some of the graphic panels installed at the back of the showcases include a narrow ledge for displaying objects that are referred to in the text. In some places, text is located directly below the ledge, making it difficult to read. This is a common error, which is easy to avoid, yet tends to be made by graphic designers who plan in two-dimensions without considering three-dimensional implications.

The university library is fortunate to have a space dedicated to temporary exhibitions. The light levels are relatively low for obvious reasons, but also quite flat, which does not do justice to the treasures on display. This could be improved by some judicious changes - adjusting the colour temperature of the lights, mixing floods and spots to pick out artefacts and by tilting horizontal objects towards the visitor.

The Sedgwick has the opposite problem: large external windows allow light to stream into the gallery. Whereas this is not a problem for geological specimens, it does affect the display of light-sensitive material, which has been replaced by facsimiles.

Perhaps this is why the two exhibitions complement each other so well. The strengths and weaknesses of one venue are counterbalanced by the other. Ultimately, it was the original artefacts, resonating with historical and cultural associations, which left the greatest impression.

This is best encapsulated by the words of one visitor who wrote in the comments book: "Wow - does all this really belong to you?"

Maria Blyzinsky is a freelance museum consultant