Reentrant wrote:
> On 14/03/2011 11:09, Bernard Peek wrote:
>
>>
>> ... The type of glass pan that can be put on direct heat
>> is a comparatively new invention.
>
> Maybe, but glass test-tubes and conical flasks have been used over
> Bunsen burners for a very long time.
>
Much thinner walls. less likely to crack.