In my recent post about an incomplete indexed birth, I noted that the 1866 birth of male-baby Curtis was a very late birth for the child's mother, Catherine, and I wondered if the incomplete index entry may have signaled that the child died at or soon after birth. I had three reasons for this question: * I figured that Catherine married no later than 1838, since her first-known child (John) was baptized in May 1839, and that she would have been age 15-20 when she married. That would make her birth date 1818-1823. If those dates were correct, in 1866 she would have been age 43-48 * There was a six-year gap between the 1860 birth of what I had previously assumed was her last-known child (Martha Elizabeth) and this 1866 birth. * She had already borne at least ten children, and surely that could have affected her ability to deliver a healthy baby in her 40's. Now I am wondering what the typical successful childbearing period was for women in Dublin of the 1800's. I don't have an answer yet, but I've just come across a very interesting 2000 article on estimating what's called "intergenerational intervals." The article is rather technical because it concerns work on genetic mutations across generations, and the importance in that work of what number is used as the length of a generation, but it's worth scanning. Of note is that the authors' data came from generations of a largely Catholic population in Canada. Here's the concluding paragraph: "In summary, our results may be more applicable to studies on populations covering a relatively recent period than to those going back to prehistoric times. Nevertheless, without any other reliable evidence on the length and evolution of intergenerational intervals in human populations, we suggest that the average value of 30 years per generation should be chosen instead of the usual 20 or 25 years." Source: New Estimates of Intergenerational Time Intervals for the Calculation of Age and Origins of Mutations, by Marc Tremblay and Hélène Vézina. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1288116/ PJ, Texas