Barrie developed a passion for collecting beautiful Victorian Vaseline (uranium) glass in his retirement, stimulated by his years of working for the nuclear industry.  In his own words, this is what it is:

"Mention the word radioactive  and most people will recoil in horror. Yet radioactivity has been with life on the world since it first began. Nothing is more natural than natural radioactivity. It is suprising just how common radioactivity is. Items we may handle in everyday life could be radioactive. Thorium, used on gas mantles, is radioactive. Potasium is radioactive.

Uranium is another naturally occuring radioactive element and it has uses other than making nuclear weapons or as fuel in atomic power stations. It is an element that gives a beautiful colour to glass and has been used in the glass industry for about 200 years.

For nearly 20 years I have been researching the use of uranium in glass. Its use in modern times is not common, mailnly due to rules and regulations, but a few glasshouses still produce glass coloured with uranium. 

What is so special about this type of glass? It is sometimes known as Vaseline Glass for the oily greenish yellow colour of Vaseline can be reproduced by using uranium in the glass melt. It also can produce other colours as well. To learn more about it read my two books on the subject. They not only contain details about the uranium in selected glass ware, but also glass densities, attributing glass, and dating glass. 

The density of glass is a most important aid to attributing a piece of glass. Every glasshouse tended to use its own basic mix from which it constructed glass of variuos colours. Thus the density of most of the items from any particular glasshouse will be the same. By establishing the characteristics of glasshouse densities the researcher has a good starting point from where to start the search."

Characteristic densities are quoted in both of his books for a number of English, American and Continental glasshouses.