Theory:

[Anna Sewell was an English writer of children’s classic ‘Black Beauty’. Although it has to come to be treated as a children’s book, it was originally meant for those who took care of horses. She talks about kindness, sympathy and understanding in the treatment of horses.]

     One morning in the autumn, my master had to go on a long journey, John harnessed me to the new cart. I liked too pull as it was very light and the high wheels rolled along so smoothly.

     It was about to rain, the weather was very windy and dry leaves blew across the road. Master, John and I went along merrily till we came to the toll gate at the entrance to the low wooden bridge. The river banks were fairly high so the bridge, instead of raising in the arc over the river, went across just level. In the middle, if the river was full, the water would be nearly up to the foot of the bridge. There were good sturdy rails on both sides though, so people were not afraid.

     The man at the toll gate said that the river was rising fast. He feared it would be a bad night. Many of the fields were already under water. In one low part of the road, the water was halfway up to my knees. But the cart was so good and master drove gently, so it did not matter.
Explanation:
  
Anna Sewell has penned the book "Black Beauty", which became a bestselling book and a children's classic. She had written the book for people those who took care of horses and worked with horses. She has prescribed the ways to treat animals with sympathy, kindness and how to treat the horses. Though intended for an adult audience, it has become a huge success amongst children also.
 
A horse is narrating the story. Autumn is the season after summer and before winter. It is a period when the weather is cool, rainy and trees start to shed its leaves. The horse's master had decided to ride the horse cart and leave on a journey. A person named John fixed a set of straps on the horse to attach him to the new cart. The horse said he liked the new cart as it was light-weight and the wheels went around smoothly. It felt light for the horse to pull the cart.
 
horse cart2.png
The new horse light-weight horse cart!
  
It was very windy and about to start raining at any time. The dry leaves that had fallen off the trees flew across the road due to the winds. The horse, his master and John rode along cheerfully till they reached the toll gate. Tollgate is a place where gates/barriers are placed, and travellers should pay an amount to cross the place further.
 
tollgate.jpg
Tollgate - pay to proceed!
  
The toll gate was the entrance to the low wooden bridge. The bridge did not arch over the river, as the banks were usually high - it was just at crossing level. If the river was full, the water would fill up till the foot of the bridge. However, since there were solid, strong railson both the sides of the bridge, people were not afraid to cross the bridge, even in peak season.
 
wooden-bridge-986345_1920.jpg
The wooden bridge on an autumn evening.. the river level continued to rise fast!
 
There was a man at the toll gate who warned them that the river level was rising fast and it may not be a good idea to cross the bridge now. He said many fields had been submerged in the water already. In a low area on the road, the water was already up to the horse's knees. But the horse said the cart was new and good, and the master rode him softly, so they need not worry.
  
Meanings of difficult words:
  
No.
Words
Meanings
1
classicjudged over a period of time to be of the highest quality
2
harnessedfixed a set of straps by which a horse is fastened to a cart
3
sturdystrongly and solidly built
4
toll gatea gate across a road or bridge where travellers must stop and pay, to proceed
Reference:
State Council of Educational Research and Training (2019). Term-1 English Standard-8. When Instinct Works - Anna Sewell(pp. 145-151). Published by the Tamil Nadu Textbook and Educational Services Corporation.