#1: June 24th 1899
Can be found in the very first room you wake up in, on the table.

#2: Edwin and Enoch's Diary
In the attic, nearby the lantern, you can crawl underneath some planks to find the note.

#3: February 14th 1899
In the hallway immediately after leaving the attic, in the second room to the left in the middle drawer.

#4: November 7th 1899
In a desk drawer in Mandus' office.

#5: Clockwork and the Soul
In the hidden pathway, stapled near one of the see-through paintings.

#6: Edwin and Enoch's Diary
Right at the beginning on a table to your right.

#7: Dieses Herz ('This Heart')
In the banquet hall to the left of the main hall, on a music stand next to a piano.

#8: December 20th 1899
On a drawer in front of the (initially locked) room with the sleeping pig monster in it.

#9: Old Sallie I the Doll's Cottager
After the pig monster escaped, it can be found inside the bedroom in a drawer.

#10: June 3rd 1899
Right after you start, lying on a barrel besides the broken staircase.

#11: August 19th 1899
In the storage room behind the blocked door, accessible via the walkway after you fixed the third fuse box.

#12: August 22nd 1899
In a desk drawer in one of the offices right at the start, nearby the phone.

#13: May 1st 1899
In another desk drawer in one of the offices, not far from the first note in this chapter.

#14: October 11th 1899
In the passageway after the offices, lying on a box.

#15: September 28th 1899
Within a small storage room in the fuelling station, near the open window.

#16: Delivery Schedule
Lying on the transporter outside in the alley.

#17: November 23rd 1899
Inside of a side room right after you enter the church.

#18: Father Jeremiah's Journal
In the storage room where you also find the candlestick, sitting on a box.

#19: These final thoughts
In the underground passage, sitting on a table next to the cages (just before the staircase with the monster scare)

#20: October 17th 1899
In the second drawer in the office above the piston hall.

#21: October 18th 1899
Just to the right on the table after entering the piston control room.

#22: October 21st 1899
In the middle of the lower area of the piston hall, where the pig monster roams, turn left and backtrack a bit. The note is on a workbench near a fence that separates the left side of the hall.

#23: April 30th 1899
In the coal conveyor area, on a box next to the facility map.

#24: July 15th 1899
By the cupboards in the room with the examination chair and lamp.

#25: a warning
In the low temperature storage on a table next to the dispenser.

#26: August 20th 1899
After the first room of the holding pens, sitting on one of the shelves in the hallway.

#27: August 4th 1898
After crouching through the hallway with the busted pipes, it lies on the ground immediately to the right.

#28: October 22nd 1899
In a small room to the right immediately at the beginning of the chapter.

#29: August 1st 1899
In the room with the valve for the first sluice gate.

#30: February 17th 1899
In the room with the valve for the second sluice gate, on the shelf hidden behind a crate.

No notes to be found in this area (they'd probably be wet and unreadable anyways).

#31: March 15th 1899
At the start of the chapter, on one of the shelves at the end of the room.

#32: December 29th 1899
On the floor with the pig masks lying around, in front of the ladder.

#33: August 31st 1899
On the pressure regulator control panel.

#34: December 1st 1899
Lying in front of you on the ground right as you regain consciousness.

#35: October 25th 1899
After going through a small wooden hut, immediately turn right into one of the apartments. Upstairs, the note rests on a table.

#36: October 24th 1899
After ending up on the road, turn right and go beyond the stacked crates. You'll find a house in which a woman gets attacked by a pig-man, the note lies in front of the scene.

#37: December 23rd 1899
After entering the building through the cellar window, the note is on a box in one of the boarded up rooms, accessible by crouching underneath the planks.

#38: October 25th 1899
Nearby the exiting lift, there will be a huge stack of crates. Crawl your way through it to find the note.

#39: October 25th 1899
At the end of one of the walkways by the iron butler.

#40: October 27th 1899 - 1
In the room where you throw the container into the machinery, it is pinned on the wall near the entrance.

#41: October 27th 1899 - 2
After the act of sabotage, in the area with the vault doors, there is a room with stacked boxes, the note resting on one of them.

#42: December 2nd 1899
After going into the Tripery, at the end of the hallway just on top of the stairs, the note is nailed to the right-hand wall.

#43: 25th December 1899: If You Should Find This
At the beginning of the chapter, pinned right next to the facility map.

#44: December 28th 1899
The final note is on one of the upper catwalks at the beginning of the level, lying next to a teddy bear on the ground.