326 H'car and Tear of Agricultural Sleajii-Eiir/t'ncs. 
The fire-box of tliis engine lasted a much k-ss time than 
usual ; the cost of repairs up to the time of its renewal was 
51. 18s. a year. 
We have selected these detailed statements of the costs of 
repairs from a great many similar ones lying before us, and 
which we omit, as they would only crowd the pages of the 
Journal without giving any additional information. We have 
returns of the cost of repairs of at least 20 portalile engines, 
varying in amount from 4/. to 14/. yearly for an S-horso engine, 
exclusive of the cost of new fire-boxes. When so much depends, 
not only on the amount of work done, the quality of thp water 
used, the care and intelligence of the engineer, but also on the 
inherent difference existing between two engines turned out of 
the same workshop, it is not easy to make an average estimate of 
the cost of their repairs. 
By far the most costly item in this account is the renewal of 
the fire-box, which, Avith carriage, will cost from 35Z. to 45/. ; and 
there is no surer test of the treatment which the engine has 
received, than the early and repeated recurrence of this demand. 
I am informed by a friend that his engine— now in its fourth 
year of use — already requires a new fire-box, although it has 
worked but once a week, and been supplied with soft water. 
My friend, however, is not surprised at this, because he has left 
the engine entirely in the hands of a farm labourer. 
An eminent maker informs me that with good management 
the fire-box of a portable engine used 2 days a week will last 
at least 7 years. Several instances of its lasting 10 or 11 
years, when used twice a week, have come within my own 
knowledge. 
To show how much this outlay may be diminished if an 
engine be well attended to and protected from dust and damp, I 
give the following extract of a letter received from the owners of 
a 5-horse-power portable steam-engine, used in an adjoining 
silk-mill, and kept constantly under the care of skilled me- 
chanics : — " The engine was worked in the mills about 6-h years, 
and about 2 days in the week during the whole of that period. 
The repairs done to it were not extensive. The tubes at the fire- 
ends were once caulked round to stop leakages, and afterwards 
8 new tubes and 2 new. collars were put in, the cost of the whole 
of which was about 8/." This statement does not pretend to 
include every item of repairs ; but after C^^ years there was 
no sign of injury to the fire-box of this engine, showing how 
much the outlay depends on good treatment and favourable cir- 
cumstances. 
