Analysis: At last there's light at the museum of everything

THE National Museum of Scotland is a masterpiece of Victorian architecture, but it had become shabby and begun to look like an anachronism - once beautiful, and cosmetic surgery had not improved on age.

Attempts to update the building began to look shabbier than the fabric they were meant to improve, while its collections seemed too vast and heterogeneous ever to make sense. No longer is any of that true. The place has been reborn, light, bright and miraculously coherent.

You enter at street level to a space carved out of vaulted storage cellars. Above, the main museum hall is just a great luminous space. A few choice objects punctuate it, but the main displays are in the galleried halls behind. Before, you had no sense of how the bits of the building related to one another. Walls closed arches. Windows were blocked off, spaces cut up. All that is gone. The building breathes again. Standing in the centre of the main hall, you can see through to Potterrow at the back. The galleried halls are linked by open arches. There are vistas now where everything was once shut off. You have a sense of direction.

A new glass lift and an escalator have been installed to take you up through the floors. Where there were once narrow, closed-in balconies, you can see out across the city. Gordon Rintoul, the museum's director, told me that formerly only 5 per cent of visitors ever ventured upstairs, but I don't think it was just the stairs that put people off. The balconies and the spaces off them were unhappy places. Even the objects looked ill at ease. Now with the oak floors restored, light paint everywhere and lots of glass revealed, all that has changed. The museum is a comfortable place to be at all levels.

• Video: Behind the scenes at the revamped National Museum of Scotland

But if the building is reborn, what about the collections? They are as diverse as ever. This is, after all, one of the largest general museums in the world; it is, in short, a museum of everything. There are 16 new galleries and 8,000 objects on display, ranging from the natural world through science, world cultures and much else. Throughout, says the director, the displays follow the principle that less is more. But what he has also done is link them through two distinctive Scottish threads: the Scottish diaspora and the Scottish contribution to invention and discovery. These vast collections cannot all be linked back to Scotland, but enough can be to help us make real sense of them.

In the 19th century, when the collections were being assembled, there were Scots all over the world and many of them favoured their homeland by sending back objects from exotic places. Annie Royle Taylor was the first British missionary in Tibet, for instance, and there are extraordinary costumes from there. John Brander was a Scottish entrepreneur who married a Tahitian princess. Her gigantic wooden feasting bowl is one of the choice objects in the main hall. Everywhere you find links like this. Costumes, tools weapons, musical instruments, whole lifestyles from the Arctic to the Pacific are represented, often with unique objects that came to the museum early in its history. A beautiful Maori canoe came with the collections of the former Edinburgh University Museum, the place where Darwin once scratched his head over fossils and James Hutton's new theory of the world's immense antiquity. Like many of the objects here, says the director, this canoe has never been displayed before. There has been new research and new discoveries within the collections.Inventors and pioneers give a different thread. A lighthouse lamp designed by Robert Stevenson, Alexander Fleming's medals, the examples are numerous, but for me one of the most striking objects in the museum is a Dunlop tyre, given by its inventor John Boyd Dunlop himself. Made in Edinburgh of Arbroath sailcloth and rubber, it is, in fact, one of the first two tyres ever made. Dunlop made them for his son's bicycle. This is the front wheel. The back wheel has been lost. Behind is a photograph of his son on his bicycle.

This kind of thing is the key. These vast collections are now rooted. They have a sense of place, of belonging. This is still a museum of everything, but it is now distinctively a Scottish museum of everything.

That is what is really new.

• Duncan Macmillan is the visual arts critic for The Scotsman