1892 birth records for Gmina Miastkowo are kept in: Archiwum Pa?stwowe w Bia?ymstoku Oddzia? w ?om?y 18-400 ?om?a, al. Legionów 36 tel: (86) 473-53-01 fax: 473-53-02 email: email@example.com www.bialystok.ap.gov.pl/lomza/
You can write in English, but their answer will be in Polish. Their answer will provide you a reference number, which you will use to make the initial payment (one hour of research is 55 zlotys,plus 2 zlotys for a A4 copy, accordingly to http://www.bialystok.ap.gov.pl/english/index.html)http://www.bialystok.ap.gov.pl/english/index.html). It shouldn't cost you more than that, since you know place and date of birth (even better if you tell them day and month and parents' names).