It contains approximately 300 high quality black and white photographs. The historical detail in these images is amazing and one could easily spend years scrutinizing them. It is a very big book (approx. A3), about 2.5cm thick (not including the hardback cover) - no casual read this. There is a large image on nearly every page (most are full page, some even cover 2 full pages), so there's a minimal amount of text, although it does manage to say everything that it needs to.
The RRP is £40 and should not be tempted to pay more than this (especially for a used copy), when it's temporarily out of stock (for example), not because it's not worth it, but because you just don't need to - be patient! (WH Smith were selling it at £26 delivered recently.)
So, why only 4 stars? Well, because I was a little disappointed by the lack of nineteenth century images; in my opinion, the title of the book is slightly misleading: there is in fact one 1870 and one 1885 image, the rest are 1890-99, 23 images in all, representing only ca 8% of the total book. Moreover, there are 7 images from the period 1946-49 - the title is '1870- 1945'? Perhaps, I am being a bit petty there, but it's worth knowing that ca 70% of the books images date between 1900 - 1914, with a heavy concentration between 1906 - 1910; the period 1920 - 1949 represents ca 22%, with a fairly even distribution over this period.