Calculating in chess books

I find it easy to calculate lines when I watch videos when someone mentions a variation without playing it out but for whatever reason, when I read chess books the variations become a bit difficult even though the length of the variations is more or less the same. I have a chess engine to consult but I try to get my self to getting the habit of reading a chess book without an analyzer. 

To sum up, I want to know two things:

1.I want to know if it is possible to read chess books without any engines or analysers

2.If 1 is true,I want to know how to improve your calculation to be good enough to where I can read such books with ease.

3. if 1 is true,I want to know if reading chess books without an analyser can end up giving me such a skill.

Try playing blindfold chess or try notating from memory a game you played or studied. To wit: a favourite of mine, played in 1862 in London

1.e4 e5 2.Nf3 Nf6 3.Bc4 Nxe4 4.Nc3 Nc5? 5.Nxe5 f6 6.Qh5+ g6 7.Bf7+ Ke7 8.Nd5+ Kd6 9.Nc4+ Kc6 10.Nb4+ Kb5 11.a4+ Kxb4 12.c3+ Kb3 13.Qd1#.

I typed this notation without looking at a chessboard. I can do this with more than a dozen historic games, including my round 5 win in the 2012 Collyer Memorial Tournament (the game was 38 moves). I cannot read chess books "with ease", but can read some variations with clear visualisation of the board in my imagination.