A CURIOUS CANADIAN IRON 311 NE, 387 



water, as our lake ore is, it of course has great freedom of move- 

 ment, and we therefore find it in flat concretions, more or less 

 porous and circular in outline ; the general appearance amply 

 justifying the term " cake ore," which is locally applied. These 

 concretions vary much in size, some of them being no larger than 

 mustard seeds, others eight or ten or more inches in diameter. 

 Frequently the larger cakes are joined together and form masses 

 looking not unlike batches of a certain kind of bun commonly 

 exposed in the shop window of every confectioner, and made by 

 coiling a strip of dough round and round a piece of itself. 



The ore is not found over the whole lake bottom ; it occurs 

 along the whole margin, and also well out from shore where 

 streams enter the lake, the distance of the ore deposit from shore 

 depending, of course, upon the volume of water carried by the 

 streams and the velocity with which it enters the lake. Certain 

 strips of ore occur at a considerable distance from the shore and 

 in as much as sixteen feet of water. These deep-water, mid-lake 

 deposits denote probably the courses of former streams which are 

 now nonexistent, owing to some change of level. 



Not only is this lake an iron mine, it is more; it is something 

 like the widow's cruse of oil of which we read in Holy Writ the 

 supply is being constantly renewed. Vast amounts of iron still 

 exist in the surrounding sands. Vegetable acids are formed 

 from the decay of each year's vegetation, and each year the drain- 

 age carries into the lake and deposits there a large amount of 

 iron. This is no mere theory : one can actually see the deposition 

 of the ore along the margin, and, moreover, it is found in actual 

 working ; if a certain spot be worked out, it will in a few years 

 again yield ore in paying quantity. 



Lake ores are abundant in northern Europe,* but, so far as 

 the writer's knowledge extends, Lac a la Tortue and a neighbor- 

 ing lake are the only instances of the kind in North America. 

 The ore is extracted from our lake mine by hand and by power. 

 The shallow margin is divided into sections and allotted to suit- 

 able parties who may desire to work them and who are paid at a 

 specified rate per ton of ore raised. Two men generally work in 

 company. Their implements are a shovel, a strong circular 

 sieve, and a rough hand barrow. When work is to be begun the 

 workmen remove shoes and stockings and use their feet in search- 

 ing for ore which lies imbedded in the soft sand, nothing coarser 

 than sand, except ore cakes, being found in the lake. Guided by 

 their feet, the workmen put down their shovels and bring to the 

 surface a quantity of ore and sand which they throw into their 

 circular sieve. This is then held below the surface of the water 



* Very interesting details concerning the ores are found in Percy's Metallurgy. 



