The amount of shipments of ore for 1859, from Marquette to the ports below, reaches 75,000 gross tons in round numbers, and the shipments of pig iron, 6,000 gross tons more. To this must be added the amount at Marquette when navigation closed, the amount at the mines ready to be brought down, and the amount used on the spot. This will give a total product of the iron mines of Michigan for the past year of between ninety and one hundred thousand tons. These mining companies simply mine and ship the ore and sell it. Their profit ranges between seventy-five cents and one dollar per ton.

The quality of the iron of Lake Superior is conceded by all to be the best in the world, as the analysis of Prof. Johnson, which we reproduce, shows. The table shows the relative strength per square inch in pounds.

Salisbury, Conn., iron58,009
Swedish (best)58,184
English cable59,105
Centre county, Pa.59,400
Essex county, N. Y.,59,962
Lancaster county, Pa.58,661
Russia (best)76,069
Common English and American30,000
Lake Superior89,582

The manufacture of pig iron at Marquette will probably be carried on even more extensively as the attention of capitalists is directed to it. The following may be considered a fair statement of the cost of producing one ton of pig iron at the Pioneer Iron Co.'s works:

1-½ tons iron ore, at $1.50 per ton$2 50
125 bushels charcoal at 7 cents per bushel8 75
Fluxing50
Labor2 50
Incidental expenses1 00
——
Cost at the works15 00
Freight on R. R. and dockage1 37
——
Cost on board vessel$16 36

The quantity of wood required for charcoal for both furnaces, is immense. The pioneer furnace requires 2,500 bushels of coal in twenty-four hours; and in blast as they are, day and night, for six months, and at a yield of forty bushels of coal to a cord of wood, it would require 15,000 cords of wood to keep them going. The company has had 120,000 cords chopped this season. This vast consumption of wood will soon cause the country to be completely stripped of its timber. Coal will then come into use. The business of manufacturing pig iron may be extended indefinitely, as the material is without limit, and the demand, thus far, leaving nothing on hand.

These facts exhibit the untold wealth of Michigan in iron alone, and point with certainty to an extent of business that will add millions to our invested capital, dot our State with iron manufactories of all kinds, and furnish regular employment to tens of thousands of our citizens, while our raw material and our wares shall be found in all the principal markets of the world.

The superior fish, found in such profusion in our noble lakes and rivers, while they afford a highly-prized luxury for immediate consumption, from one of our leading articles of export, and are very justly regarded as constituting one of our greatest interests.

It is estimated by men of intelligence that the value of our yearly catch of fish is greater than that of all taken in fresh waters in the thirty-two remaining States of the Union. This may at first blush seem like a broad assertion, but it is no doubt strictly within bounds. If the claim be not too much of the nature of a truism, we may add that so far as quality is concerned the superiority of our finny tribes is even more strongly marked than in regard to quantity. In the sluggish streams that abound in "ten degrees of more effulgent clime," the fish partake of the slimy properties of their native element; it is only in the limpid waters of the North that they are found of flavor so unexceptionable as to please an epicurean taste, or exalt them to the dignity of a staple of commerce. Fish possess peculiar qualities to commend them as an article of food, independent of the arbitrary preference of the epicure. They are universally esteemed as a wholesome and nutritious diet. In that pleasant work, Irving's "Astoria," a tribe of Indians are described who subsisted entirely on fish, whose rotund appearance contrasted strongly with the physique of their brethren of the forest. The profusion with which the finny tribes propagate their species is a peculiarity said to be imparted to those who partake freely and regularly of them for food, a supposition which would seem to be strongly supported by facts. Fishermen are proverbial for the number of their descendants. One of the tribe who dries his nets in Sarnia, is the happy father of nineteen children, and we can cite numerous proofs almost equally striking in support of this theory.

The fisheries have always been a leading subject in the government policy of seaboard nations. They are a prime source of revenue, and have been the cause of numerous wars. The serious controversy between the United States and Great Britain concerning the Newfoundland fisheries, is still fresh in the memory of our readers. Recently the earnest attention of the French government has been directed to propositions for the artificial propagation of fish, as a means of affording good and cheap food to the people at a merely nominal cost. The gradual diminution of the species, as well as the ultimate extinction of the large birds and quadrupeds, is everywhere a condition of advanced civilization and the increase and spread of an industrial population. To provide a remedy for the evil, the science of pisciculture has latterly attracted no small degree of attention, and, at this time, gentlemen prominently identified with our fishing interest have it in contemplation to stock lakes in the interior of Michigan with a view to the prosecution of the science.