The earliest instrument proposed for testing the strength of powder was, I believe, Bourne’s “engine or little boxe,” which, he says, was “very necessarie to be used.”[475] Whether he invented it himself or not, it is impossible to say: he tells us, “some of (the inventions) I have gathered by one meane and some by another, but the most part of them hath been mine own.”[476] The engine was a wretched one. The powder to be tested was ignited in a small metal cylinder with a heavy lid (working on a hinge) which when raised could not shut of itself. The angle through which the lid was raised by the explosion indicated the strength of the powder. A better instrument was that described by Furtenbach in 1627.[477] It differed from Bourne’s “little boxe” in that the lid was only laid upon the cylinder. When the powder exploded the lid was blown upwards along two vertical wires which passed through it; but it could not descend again of itself, being held in the place it reached by iron teeth (like those which supported the lid of Bourne’s box). Nye describes this instrument, and suggests that the comparative strength of powders should be further tested by measuring the penetration of pistol balls into clay, and the ranges of projectiles fired from a small mortar.[478] This is, I believe, the first proposal of the _mortar éprouvette_, 1647. The French certainly adopted them before 1686, often though it has been said that they then introduced them. On the 18th September of this year Louis XIV. published an ordonnance complaining of “the variety of eprouvettes” in use for testing powder, and directing that for the future no powder should be accepted unless 3 oz. of it could throw a ball of 60 lbs. 50 toises (320 ft.) from the Government pattern mortar.[479] In a previous ordonnance (April 16, 1686) the King had protested against the bad charcoal (_de méchante qualité_) constantly employed; against impure saltpetre (_rempli de graisse et de sel_), insisting upon the exclusive use of saltpetre “de trois cuites”; and against insufficient incorporation (_dix ou douze heures ... au lieu de ... vingt quatre heures_).[480] But he marred the reforms he made by taking the unaccountable step of introducing one powder, of the same composition and size of grain, for all arms.[481] For this blunder the French afterwards paid in blood, especially during the Peninsular war.[482]