JOHN SCOTT RUSSELL: 1838

Left: John Scott Russell (1808-1882) Russell wrote an extended criticism of the rotary engine concept called "Fallacies of the rotary steam engine" which was printed in Mechanics Magazine for April 1838, starting on p192. He was born near Glasgow in 1808. He graduated from the University of Glasgow in 1825, and moved to Edinburgh University where he taught mathematics and natural philosophy. In 1834, while conducting experiments on the design of canal boats, he discovered the soliton. (external link) Russell moved to London in 1844. He worked on the design of ships, becoming a director of a shipbuilding company. Isambard Kingdom Brunel who made him a partner in building the Great Eastern, but there were problems; Russell was in financial difficulties and the two men disagreed on aspects of the design and construction. (The Great Eastern was eventually launched in 1858) He was expelled from the Institute of Civil Engineers for some questionable arms deals during the American Civil War.

Russell was a great scientist but a mediocre businessman and his reputation suffered from his disputes and financial irregularities. He died a relatively poor man in 1882.

John Scott Russell's main criticisms of rotary engines were:

• The Crank Fallacy; in other words, the error of advocating rotary engines because they avoided an entirely imaginary problem with cranks and connecting rods. It appears to have been believed by some people that because the connecting rod was not always acting at right-angles to the crank, the loss of mechanical advantage meant a loss of power. For example Thomas Masterman, the patentee of a rotary engine in the form of a steam wheel, claimed that the usual crank system absorbed half the power available in the steam supplied. This is obvious nonsense, because if the crank system had somehow been absorbing power, it would have eventually got red-hot. John Scott Russell devoted pages of deeply tedious analysis to proving that there was no power loss.
• Greater bulk; in other words a rotary engine of the same power as a reciprocating engine would be bulkier because the steam at the inner parts of the engine worked with less mechanical advantage upon the rotor.
• Uneven wear; the outer parts of the engine moved at a greater linear velocity than the inner sections, wearing faster and considerably complicating the task of keeping the seals steam-tight.

"There are other defects to which this species of engine is particularily liable- to vacuities and losses at the valves and passages- to irregular action, and collisions and shocks from the action of the parts upon one another..."

A VIEW OF AMERICAN ROTARY ENGINES: 1847

Left: This commentary on rotary steam engines appeared in Scientific American in June 1847. Even at this relatively early date, there appears to be considerable cynicism about the concept. The bit at the end about "the excess of centre speed" is wholly opaque to me.

A WORD FROM GEORGE STEPHENSON: 1848.

Left: George Stephenson (1781-1848) Below are presented extracts from the minutes of a General Meeting of the Institute of Engineers on 26 July 1848; at this period more than 50 patents for rotary engines had been taken out. While several of the participants appear to come from the pages of Terry Pratchett, this is not actually the case. These are the real names. THE PRESIDENT is none other than George Stephenson.

MR ONION then stated that his engine* had been working for some weeks at the Derby station, by permission of Mr Kirtley, the Locomotive Superintendant of the Midland Railway; and during that trial, experiments with his and another engine had proved that his effected a material saving in fuel.

THE PRESIDENT said that it appeared to him to be impossible that such could be the case. The engine might have answered at one trial, but it might fail at the next; and one trial was by no means a sufficent proof.

MR SLATE observed that there was one important desideratum which he desired to see obtained in the Rotary Engine- namely, some method of packing tightly. That had never yet been found. He had paid much attention to the Rotary Engine, and had seen approaches made to an efficient system of packing, but none had been so perfect as to render the rotary principle equal to the crank. Mr Onion had told them his engine was more simply packed than the common engine.

MR ONION said that Mr Scott Russell**, who had written on and patented several Rotary Engines, confessed to him that he (Mr Onion) had succeeded in overcoming difficulties which had hitherto been found to be insurmountable, such as making his engine steam-tight, and also in doing away with the usual noise*** of the Rotary Engine.

JOHN BOURNE: 1853

"It cannot be said that any one of the multitude of rotatory engines yet tried has been completely successful; nevertheless we are by no means of opinion that a good rotatory engine will never be discovered, but, on the contrary, believe that the reciprocating engine will yet be superseded by a rotary contrivance of a far simpler kind than any one now contemplates."

From A Treatise on The Steam Engine in Its Application to Mines,Mills, steam navigation and Railways by the Artizan Society, ed John Bourne, pub 1853 Longmans