The evolution of explosives:
The year 1597 saw the use of gunpowder for quarrying for the very first time.  This momentous event took place in mines belonged to Giovanni Martinego, situated in the Vincenza area.  We learn from early reports that these mines were made to explode by ramming the explosives into cracks in the rock to be quarried. 

The evolution of explosives has been constant and fast-paced.   People were well aware of the advantages and significance of this new and wonderful material for the quarrying industry.  Gunpowder had the capacity to break up the hardest of rocks and minerals.  Previously, quarrying operations were carried out manually, with simple tools like wedges, pick-axes, sledgehammers and crowbars. 

Experimental tests were carried out, often with serious consequences, to improve the safety and performance of the explosives.  By the long-trusted method of trial and error, the proportions of various components (chlorates, nitrates, ammonium perchlorate, potassium and sodium perchlorates and glycerine) were arrived at.  These components were mixed with stabilizing, inert or colloidal elements (paraffin and Vaseline), to guarantee safety during all stages of activity – preparation, transportation and final use.

Several years down the line, special explosives were manufactured for underground use.  These could be used even in the presence of firedamp, which on contact with air and inflammable powders could explode easily, especially when the mixture reached 9.5 per cent gas, and 90.5 per cent air.  

Important requisites / precautions while carrying out underground quarrying 

• Extreme care should be taken to ensure that these mixtures are prepared by accurately calculating the amount to be used.

• The explosive should also be rammed thoroughly into the cracks or holes. 

• Caution should be exercised to ensure that the explosives do not emit toxic gasses.  This is possible if the explosives are of the complete oxidation type.

• The power of these explosives should not exceed the safety limits during explosion.

• All conventional safety rules and measures should be strictly adhered to, both during use and transportation.  This includes all workers being fully knowledgeable about the main characteristics of explosives used in the quarry.