and on Miscellaneous Inventions at the Birmingham Shoiv. 247 
classes, provided that the operations in each class could be 
performed without adding or taking away parts ; but by another 
regulation, no exhibitor might enter more than one machine ot 
the same construction lor competition in any one class. 
The Judges of reaping-machines were Colonel Henry Valen- 
tine Grantham, of West Keal Hall, Spilsby, Lincolnshire ; Mr. 
James VV. Kimber, of Fyfield Wick, Abingdon, Berkshire ; and 
Mr. Thomas Rigby, of Darnhall Mill Farm, Winsford, Cheshire ; 
with Mr. W. Anderson, C.E., (of Messrs. Eastons and Anderson, 
Erith Iron Works, Kent), as Consulting Engineer, and Mr. 
John Algernon Clarke, of 109, Ladbroke Grove Road, Notting 
Hill, London, as Reporter. On Monday, July 17th, and three 
following days, these gentlemen made a careful examination of 
the machines entered for competition in the Society's Showyard 
at Birmingham, having regard to the condition that no dupli- 
cates were admissible in any one class, and also to the following 
instructions : — 
"4. The Judges will be requested to observe that it is left to their dis- 
cretion to select the implements for trial from those specially entered for 
competition for the Society's Prizes, as well as, if they consider it desirable, 
from those not so entered. 
" 5. The Judges will decide on the merits of the work done by any agri- 
cultural machines to which steam or other power is applied ; but they will be 
required to pay every attention to the report of the Consulting Engineer, as 
to the power used, the mechanical construction of the machine, and the 
quality of workmanship and materials used. 
" 6. The Judges will be instructed to pay particular attention to the con- 
ditions relating to the qualifications each machine should possess, and to the 
speed and pressure as given." 
The question, "What constitutes a duplicate?" was settled 
by the following considerations. Obviously it would not be 
sufficient to lay down as a rule that machines were not dupli- 
cates unless they were exactly similar in construction in every 
detail, of precisely the same pattern, and with precisely the 
same dimensions in all the working parts. For parts might 
differ, and yet the effect of their action might be exactly the 
same. Thus, a spur-wheel of one hundred teeth, driving 
another of fifty teeth, would produce two revolutions of the 
latter for one revolution of itself ; and a wheel of eighty teeth, 
driving another of forty teeth, would give the same result. So 
that the motions would be practically duplicates, unless there 
were some advantage gained in working, such as a lessening 
of friction on the bearings. Hence it was decided that slight 
variations in constructive detail did not render very similar 
machines eligible to compete in one and the same class, unless 
some palpable difference in operation were effected by such 
variations. 
