Sequence of Development of Speed Governors

The correct sequence of development of the speed governors mentioned is as follows:

1. Porter Governor - The Porter governor is the oldest and simplest type of speed governor. It was developed by Robert Porter in the early 18th century. This type of governor consists of two rotating balls attached to a vertical spindle. As the speed of the engine increases, centrifugal force causes the balls to move outwards, which in turn raises a lever and reduces the fuel supply to the engine. Similarly, when the speed decreases, the balls move inwards, causing the lever to lift and increase the fuel supply. The Porter governor operates on the principle of inertia.

2. Hartnell Governor - The Hartnell governor was developed by Hartnell in the mid-19th century. It is an improved version of the Porter governor and is widely used in steam engines. The Hartnell governor consists of two rotating weights attached to a vertical spindle. As the speed of the engine increases, centrifugal force causes the weights to move outwards, which in turn raises a sleeve and reduces the fuel supply. Conversely, when the speed decreases, the weights move inwards, causing the sleeve to lower and increase the fuel supply. The Hartnell governor operates on the principle of inertia.

3. Watt Governor - The Watt governor, also known as the fly-ball governor, was developed by James Watt in the late 18th century. It is a type of centrifugal governor that was used to regulate the speed of steam engines. The Watt governor consists of two rotating balls attached to a vertical spindle. As the speed of the engine increases, centrifugal force causes the balls to move outwards, which in turn reduces the fuel supply. When the speed decreases, the balls move inwards, causing the fuel supply to increase. The Watt governor operates on the principle of centrifugal force.

4. Proell Governor - The Proell governor is a more modern type of speed governor that was developed in the 20th century. It is an improved version of the Watt governor and is used in various applications, including internal combustion engines and turbines. The Proell governor consists of two rotating masses attached to a vertical spindle. As the speed of the engine increases, centrifugal force causes the masses to move outwards, which in turn reduces the fuel supply. Conversely, when the speed decreases, the masses move inwards, causing the fuel supply to increase. The Proell governor operates on the principle of centrifugal force.

Therefore, the correct sequence of development of these speed governors is 3, 1, 4, 2, which corresponds to the Watt governor, Porter governor, Proell governor, and Hartnell governor, respectively.