910
THEORY AND PRACTICE OF ENGINEERING.
for stucco, with which the facings in moellon are sometimes covered, is nearly the same asthat of the pointing, the quantity of mortar being a little greater.
Incidental Expenses on Mason's Work consist in the maintenance of the machines used,timber and cordage for scaffolding, saws, sieves, roller, pincers, &c. The tools for cuttingand laying the stones belong to the workmen: these incidental expenses amount to aboutone tenth of the labour.
Iron-work. — A smith usually works, winter and summer, twelve hours per day.
There is employed in themanufacture of a kilo-gramme of iron
Loss of iron may be va-lued at
The volume of coal usedfor a kilogramme.
{
{
{
Smith andhis Assistant.
For iron of large dimensions, as ties, &c. - 0*10
For cramps, &c. - 0*40
For pins, bolts, &c. - 0*70
Of the Pri-mitive Weight.
For the first ----- 0*03
For the second - 0*08
For the third ----- 0*10
Cube Metres.
For the first - - - - 0 0001
For the second - 0 0006
For the third ----- 0*0010
For a kilogramme of iron,including carriage
Making the screw ends of bolts, according to their size, requires from 0*2 to 0*5 hours ofa smith for the screw and its nutt: with regard to the placing or fixing ironwork, if it isdone by the smith it may be valued at
Hours of a Smithand his Help.
" For the first class - 0*04
For the second - - - 0*20
^ For the third ----- 0*40
As for running in with lead, &c. it is difficult to fix a price.
Incidental Expenses. — These are considerable: as all the tools are furnished by the con-tractor, they are generally put at one-fifth in ordinary buildings, but in bridges, &c. one-seventh is sufficient.
Painter's Work. — The colours usually employed are lamp-black, red and yellow ochre,linseed oil, turpentine, &c. : to cause them to dry quickly, litharge is added. The labourof the painter is employed to grind the colours and to lay them on.
• For grinding a kilogramme f Ydlow'ochreof colour in oil [ Lamp-black -
The quantity of oil necessary for the above : —
Hours of aGrinder.
8*5
6*5
8*5
Kilogrammesof Oil.0*50*50*8
f Red ochre - - - -
For grinding a kilogramme-j Yellow ochre - - - -
Lamp-black - - - -
The colours being ground, they must then be mixed with a sufficient quantity of oil tobe in a condition to lay on.
Kilogrammesor Oil.
f Red ochre ----- 0*62
To mix a kilogramme *{ Yellow ochre ----- 0*73
(_ Lamp-black - - - - - 1*17
If turpentine is used for the above quantity, half the oil is employed with the samequantity of turpentine : sometimes one-eighth of litharge is added.
To paint a square metre two coats requires
Kilogrammes ofprepared Colour
Red or yellow on timber - - - - 0*12
Olive colours - - - - - 0*11
Black - - - - - - 0*08
The waste may be valued at a twentieth of the original weight.
Time necessary to mix and apply the colours —f Without scaffolding
For a square metre j with a flying ^(folding
Hours of aPainter.0*20*5