ready to detect

Picked up a Pettersson Ultrasound Detector D 100 from Dr Fenton this afternoon. Will attempt to scan for bats at the Carr Astronomical Observatory. He gave me some hand-written notes to ascertain the type of bat based on frequency, sound, and repetition.

It runs off a 9V "transistor" battery. Features an LED under the frequency dial for night-time use. Outputs for earphones and "tape." Ha ha. Tape?!

Curiously, as I stopped at the library to drop off a book (Nightfall), leaning my bike against the wall, I noticed one of the wall elements was broken. Too bad. Marred the whole side. And then I noticed the dark grey plate was slate! Things that make you go hmmm.