Chap. X.
VALUE OF ARTIFICERS’ WORKS
907
Masonry , valuation of. —Mortar, cutting and laying the stone.
Forming the Mortar .— The proportion of the materials used depends on their quality,as does also the waste, and which experience can alone value: it must be first ascertainedhow much a given measure of well burnt quicklime will produce when slaked ; observingthat quicklime always suffers a loss of about a tenth, on account of the core, which arisesoften from not being properly burnt. Secondly, the proportion of slaked limes and sand,or other materials used instead. Thirdly, the relation of the volume of the mixture aftertrituration, with the volume of the materials mixed. As to the labour, the slaking of thelime depends on the quantity as well as distance from whence the water is brought; it maybe valued in general at eight hours of a labourer for every cube metre of quicklime; if thewater is laid on, five hours of a labourer is sufficient.
Making the mortar requires care, and an account must be taken of the time employedfor its due mixture ; it may be considered that from 12 to 20 hours of a labourer isrequired for a cube metre. The waste in mortar may be computed at one-twentieth of its
volume.
Hubble Work or Moellon comprises the carriage of the stone from the yard where it ismeasured to the spot where it is to be used, and its adaptation, whether rough, piquet orhammer-dressed, in mass or faced, in walls or vaults. The removal is performed bybarrows when the distance is not considerable.
Hour of aLabourer.- 0-8
Loading the barrows, per cube metre
Removal with one relay of from 20 to 30 metres, the specific gravity of the
stone being 2
0*6
When the distance is greater, carts are employed, containing 0-21 cube metres, whichare drawn by four men.
To load a cart containing a cube metre of moellon 0*83 hours of a labourer.
Hours of4*767 carts,
drawn each by
four men.
{ Loading the carts containing 0*21 cube metres,three labourers to load -
100 metres going and returning -Unloading •
005800600 030
When the distance is considerable, the removal of the moellon is performed in cartsdrawn by horses: it will be easy to estimate it upon that of the removal of earth,reckoning 0-85 hours of a labourer for loading a cube metre in the carts, and observingthat each horse which draws half a cube metre of earth weighing 1500 kilogrammes, canonly draw
^ 0-5 = 0*375 cube metres of moellon.
A man with a barrow, working ten hours, will remove ^ = 16*7 cube metres of stone
to a distance of 30 metres of level ground, or 20 metres when inclined. The specific
gravity of stone being 2, the daily effective labour will be equal to 16*7 x 2 x 30 = 1000
kilogrammes moved 1000 metres on horizontal ground, and 16*7 x 2 x 20 = 668 kilogrammesmoved 1000 metres on inclined ground.
10 x 021
For the removal by carts, a man in 10 hours would remove - -- =3*547 cube
metres of moellon, 100 metres distance. ^ x ^
The daily effective labour then would be 3*547 x2 x 100 = 709 kilogrammes carried1000 metres : with respect to water carriage the value of transport depends upon variouscircumstances.
The labour required to execute a cube metre of moellon, including the labourersassisting the mason, as well as those making the scaffold : —
Per cube metre
{
{
Measuring the stone -
Throwing the stone and watering, without adjustingDitto with adjustment -
Hours of a
Masses placed dry by* hand
Masses placed rough -
Masses for walls requiring scaffolds
Per cube metre
- 4*50
- 6*50