460 The Trials of Spraying Machines at Cambridge. 
Class III. — Horse Power Machine for Distributing Bouillie Bordelaise 
or other Mixtures on Potatoes. 
No. in 
Catalogue. Names and Addresses of Exhibitors. 
4643 William Weeks & Son, Ltd., Maidstone, Price 3 71. lO.s. 
4654 Strawsons, Ltd., 77 Queen Victoria St., London, E.C. 60 gallons. 
Price 25/. 
4686 Pk. Mayfartk & Co., 16 Mincing Lane, London, E.C. “ Syphonia.” 
Price 22/. 10s. 
The trials took place on Saturday, June 23, on the farm of 
Mr. J. H. Ridgewell, Histon Road, Cambridge, in a large field 
of potatoes well adapted for the purpose. The potato plants were 
not very high, but there was ample foliage to test the distributing 
powers of the machines. 
The Judge had made up his mind that many points should 
be given to the machine that would spray the under as well as 
the upper sides of the potato leaves, for the reason that, as the 
potato fungus, Phytophthora mfestans, appears first on the under 
sides of the leaves, it is most desirable that the Bordeaux mix- 
ture should be applied there, whether it be used as a means of 
prevention or as a cure of disease. It must be admitted that 
there is considerable diversity of opinion upon this subject. 
M. Girard holds that it is immaterial whether the under surfaces 
are sprayed or not ; but, on the other hand, M. Petermann, who 
has conducted valuable experiments at the Belgian State Agro- 
nomic Station at Gembloux, states that it is indispensable to 
spray the lower surfaces of the leaves, particularly when the 
mixture is applied preventively. 
Independently of its manifest superiority in other respects, 
No. 4654 thoroughly fulfilled this important requirement, as 
every part of the under surface was covered with the mixture by 
direct spraying, and the upper surfaces equally well by the mist 
which fell upon them. Neither of the other competing machines 
was arranged to spray the under surfaces. 
The Strawsons’ Machine, as will be seen by fig. 1, is a 
light water cart, with an arrangement of pump, tubes, and 
nozzles behind for distributing liquid compositions. Its barrel, 
holding 60 gallons, is set on a frame carried on high iron wheels, 
4^ feet in diameter, with 3 inch tires. These wheels can be 
moved upon the axle and adjusted easily to suit the width of 
potato rows planted at from 24 to 30 inches apart. A powerful 
double-action pump with brass lining is fixed on the frame. Its 
lever is moved by gearing from the axles of the machine, and is 
attached to the gear of the machine by a bolt and pin, so that 
when the bolt is removed the pump can be worked by hand 
power for filling the barrel or agitating its contents. The flow- 
