search engines

I am finding Google to be a trial. I want to make enquiries like:

circa 1810 AD, cost of building a Dutch Flujt

circa 1810 AD, 8 Escudo coin, weight, gold purity, exchange rate with Florins.

I suspect that the data is there to be found and things will get better as people become more imaginative on tagging their articles.

I would like to know what tools and methods authors have found useful.