well it is on my website, you measure the width and length of the drop, divide the width by the length and multiply it by sin inverse, so you need a calculator or log book and a ruler.
ooooooooooooo sorry, I got really excited on that one! Dr. Bill Bass from the University of Tennessee I believe. He was my forensic Anthropology intstructors mentor in grad school! (at the University of Tennessee!)
Well i think ThumpyG meant visible, latent and impressed like you said but i don't know, but it would be correct i tink! we have to wait for Thumpy to tell us.