Who When Where

OK, here goes: These two photos seem to have been taken at the same time - if I am right, they are grandparents with two different grandchildren.
What date would you suggest? And are the children girls or boys? What ages?

I'm thinking these photos date from circa 1850 -- due to the (apparent) Daguerreotype casing. Daguerreotypes always came in protective cases, often made of leather and lined with silk or velvet. Daguerreotypes were sold in Britain throughout the 1840s and into the early 1850s.

Although if the actual materials used to make these cases is compressed paper and card (rather than leather and silk) the photos could be collodion positives (ambrotypes). And that would mean these photos would date c1853 to c1860.

Note: Collodion positives are often confused with daguerreotypes because they are a similar size and were also usually supplied in a protective case or frame.

Although the outside of the case appears like tooled leather, and there is a velvet rim between the inner and outer frames, I think they are the cheaper version that you describe. The front cover has been torn away from each one and I can see a wooden frame to which a leather-effect coating has been applied.
The gentleman is wearing a distinctive style of bow tie - any comments?

Sorry - there's too much glare on the photos to make out further details of the bow tie and/or the two children.
Also, I'm siding with the photos being Daguerreotype, due to the distinctive gold-coloured border surrounding both subjects.