and Miscellaneous Implements at Bristol. 
115 
cylinder faces, the valve revolves a little in the bridle, and by thus yielding 
prevents abrasion or scoring, and at the same time brings fresh surfaces into 
contact. The consequence is that wear becomes extremely uniform, and the 
irregular wear, as in ordinary valves, is entirely prevented, so that not only do 
the valve and cylinder faces last much longer, but there is also much greater 
economy of steam. The experience on the London and North- Western Rail- 
way quite corroborates Messrs. Fowler's statements. 
There is a simple and ingenious method of reducing the pressure on 
the valve. The valve bears not only on the cylinder face, but also on a 
kind of cup, h, inside the valve, — this cup being connected by means of the 
hole c with the steam space, so that the area of surface represented by the 
cup is quite relieved of pressure, and consequently the valve is more easily 
moved and will work longer. It is therefore Mr. Anderson's opinion, on 
which the Judges entirely based their award, that the introduction of the 
balanced circular slide valve is a decided gain to the agricultural locomotive, 
and deserves the recognition of a Silver Medal. 
Turton's Patent Rick Covering (^Morris and Griffin). — The importance of a 
cheap and efficient substitute for thatch has of late years been felt to be a 
great desideratum. Straw is now so dear and scarce, that it is positively 
difficult to get material ; then, again, good tbatchers are not so common as 
formerly, and, above all, however carefully arrangements are made, it is often 
impossible to prevent loss from rainfall before the thatching is done. Dutch 
barns are undoubtedly the most permanent, and in the end probably the 
most economical investments ; but such are rather landlords' than tenants' 
work, and it is not every one who can aiford the outlay ; and therefore a cheap 
substitute for thatch is highly important. The Judges considered that such 
was exhibited by Messrs. Morris and Griffin in Turton's Patent Permanent 
Eick Coverings, in felt, galvanised iron, or plain sheet iron. The invention 
consists of a series of rafters, a a, 45"xl3" of deal, fixed 3 feet apart, and 
held in position by iron rods ^ diameter, b b, kept tight by cottar pins, cccc. 
The following sketch, Fig. 21 (p. 116), shows this arrangement. It will be 
seen that the top and lower distance rods are of different construction, the 
former, which represent the ridge-board, have space for the end of the two 
rafters. The appearance of the roof, partly covered by asphalte, is shown in 
the following drawing, Fig. 20. 
The felt or iron is laid on in lengths and held in position by 
iron pins, Fig. 22, p. 116, about 2 feet long, which pass through 
the rafters into the rick, metal collars or brass eyelets being fitted 
into the felt to prevent wear, thus both timber and felt are securely 
attached on the rick. The advantages claimed for this invention 
are, (1) that it is watertight ; (2) that it is quickly fixed ; (3) 
it is cheap. Without calculating the timber, which will with 
care last for a number of years, the cost of the felt is not more 
than that of straw and labour ; the best felt can be bought for 
Qd. a yard, and I question whether a good coat of thatch, taking 
the value of the material into account, can be done at much less, 
certainly the felt, even if untarred, will last four or five years. It 
is said that a good-sized rick can be covered by two men in two 
hours ; this, however, is rather a vague statement, and the Judges 
had no means of testing the question. If all the parts were 
laid out in order, I see no reason why much time should be 
occupied, and certainly there would be a great saving over the 
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