A.S. NeneProfessor of Civil Engineering (Retd) VNIT Nagpur
Uses of Stones Making sculptures Building blocks for construction.
Sources of building stones Ref. Kashyapashilpa From hills From underground mines Riverbanks and forestsThe stones obtained from barren land, graveyard or those embedded in ground are unsuitable.Stones obtained from sites unsuitable for habitation are also unsuitable.
Classification of stones By Color Milk, Jaya flower, Buffalo’s eye, Conch,White Moon, Pearl Crystal et Indragop (insect), Rabbit’s blood orRed Pomegranate Flower etc.Yellow Flowers like, Mallika or Korandi Kajal (eye ointment), Blue lotus, Wasp,Black Vest part of peacock, black gram etc Ref. Kashyapashilpa
By Age Child Sound produced as un-burnt bricks, long or flat in shape as a leaf Young Long ringing sound like bell, soft in touch, with good smell, without pores Old Non-ringing sound, highly porous, highly weatheredStones of first or third category are unsuitable Ref. Mayamat
By GenderMale Big, rounded, which produces sparks when hit with chisel- Suitable for columnsFemale Medium size, soft in touch, broad at base –Suitable for beamsNeutral Small, broad at top, not sounding- Suitable as aggregates Ref. Vishnudharmottar Purana
Defects in building stonesLines • curvilinear (as thread), • straight (as sun rays) • parallel (as rains)Spots size. lemon fruit (15-20 mm), grape size (5-10 mm), less than 5 mm. Ref. Mayamat
Detection Of Defects In RocksMicroscopic defects in stones , which wereinvisible to eyes, were detected by applyingsome herbal paints so that the defects wereclearly visible.
Stone softening Stone with 14 angles Stone wall at Cuzco (Peru)The Incas employed certain methods to maketheir stones fit perfectly. They knew a plant whosejuices rendered the surface of a block so soft thatthe intricate fittings were accomplished.
Adamantine gluesA bonding agent was very essential for fixing idols,In wall construction, when cement and other modernmaterials were unknown.Even now, these glues were known as Astabandha,are prepared in temple premises for fixing or re-fixing images of gods.
Breaking of stone blocksHeating: The stone block is heated by make apyre of wooden logs of Palash or Tinduk trees.The heating is continued till the color of woodenlogs becomes bright red or orange.Cooling: The fire is moved to adjacent area ofrock surface. The preheated surface is cooled downquickly by pouring certain types of liquids listedbelow.•Solution of quick lime in cold water•Solution prepared by mixing buttermilk with rice paste, ripeberries.•Solution prepared by boiling Neem leaves and some treebarks. Ref. Brihat Samhita
Tempering or hardening of tools Ref. Brihat Samhita1. heating the tool in fire until it becomes red hot.2. application of paste of certain materials and / or dipping the red-hot tool in a specific solution.4. sharpening the tools. The Paste / solution used in step 2Paste made of• excreta of pigeon and rat,• powder of horns of a buffalo• milk extract of a plant (Mandar) Solution of buttermilk and ash of banana plant
Suranga –A water tunnelSuranga is a tunnels bored horizontally on the slopes of hills to get clean drinking quality water.Found in many parts of Dakshina Kannada district of Karnataka and Kasaragod district of Kerala‘Quanat’ is a similar structure used in Iran and Iraq Suranga Quanat
Building Stones The Indus valley civilization shows the use of • Tertiary limestone, •Sandstones •Mesozoic steatite.Marble cutting achieved a remarkable level ofsophistication, with the intricate undercutting inthe 11th and 12th century temples at Mt-Abu
Conclusions Different types of stones were used in different time spans Selection of the stones by texture and strength and absence of micro cracks,. Ancient knowledge is applicable even in modern times. More information on defects of rock was provided in ancient texts.