CLARKE, James Harrison or Samuel Walmsley?

[arthurk]

I expect Lesley will comment when she returns, but in the meantime, I think it says they lived in Portsmouth, and were only temporarily in Velsen.

[Lesley Robertson]

That'll teach me not to believe the census. From the Dutch Registers (site called WieWasWie, HERE free to use, has an english language (ish) search engine, records in Dutch ):

Sam Walmsley Clarke b. 20.02.1873. parents as in #10. Velsen. (I'm skipping most of the printed guff, sorry - paraphrasing) Dad was 29, a machinist (mechanic or engineer) normally residing in Portsmouth, temporarily living in Velsen, witnesses Jacob Gravenkamp (details) & Derk Slebor (details) has declared that his wife Alice Speakman, without work, resident in Portsmouth, England, temp. here had a male child called Sam Walmsley. John has a nice signature.
Also Margaretha Alice 13 March 1869. Same data but doesn't mention temp residence.
Allard 's precis is linked to the wrong page (it's linked via child, mother & father, all leading to the wrong page, grrrr) but his b. is 18 feb 1871, Velsen
Mary Kate 5.12.1874 data the same as Sam's

All kids born at "the house on the Vinkenbaan". It's not terribly far from the Amsterdam harbour complex.

I don't know which house they had, but there's a number of listed houses on the Vinkenbaan and it's suggested that one dated abt 1877 was occupied by English (they mean British, can't get it through their heads that the two are not synonyms) engineers working on the last phase of the North Sea Canal.