No. 6.

In heavy doubletrees the draught ring would be at least 5 inches behind the whippletree rings, which, with a length of 40 inches, would give a ratio of 1 to 8.

When one end of the doubletree is 5 inches in front of its position when at right angles to the line of draught, the forward horse would be working on the arm of a lever 18.25 inches long, and the hind horse would be working on the arm of a lever 20.6 inches long,-an advantage in leverage of 2.35 inches.

In plowing, with a total draught of 350 pounds, one horse would be exerting a force of 185.5 pounds and the other only 164.5 pounds, a difference of 21 pounds.

Doubletrees are sometimes made with a small shaft of wood and iron chains fastened at each end, connected in the middle by a ring, as in cut No. 7.

No. 7.

The proportions of these doubletrees vary considerably, the center draught ring being often from 6 to 8 inches behind the whippletree rings.

These doubletrees are often used in heavy draught, when the whippletrees need to be frequently lifted in changing the direction of the line of draught.

From the illustrations already given it will be seen that the proportions of this form of doubletree will produce an inequality in the draught that will quite overbalance any other desirable qualities that it may possess.

The truss whippletrees" that have been recommended on account of their "lightness and strength" are, on the same account, quite as objectionable as the forms figured above.

It will be seen from what has already been said, that the draught pins in the doubletree must be in the same line to secure an equal division of labor in all positions,-and that in any other form an "advantage" given to one horse is more imaginary than real.

It must be remembered in discussing this subject, that the effects of faulty construction in the doubletree are severely felt in heavy work where the power of the animals is fully exerted. Any additional force required under such circumstances cannot fail, in the long run, to result in permanent injury.

CLOSE BREEDING.

BY M. MILES.

A sharp and acrimonious discussion has, for a long time, been carried on between the advocates of close breeding and those who insist upon the exclusive practice of what is called out-crossing.

The arguments that have been urged with earnestness and zeal, on both sides, have failed to settle any points in the controversy.

The positive manner in which experience is appealed to by both parties, brings to mind the old fable of the discussion in regard to the color and bearings of a shield. Here, too, each party in the debate relied upon the evidence of their own senses; but the shield had two sides, only one of which had been seen by those who were engaged in the controversy.

The more modern story of the dispute about the color of the chameleon likewise furnishes a parallel case: several persons had seen it, yet they all differed as to its color; one said it was green, another said it was brown, while others said it was of some other color. Each knew that their own eyes had not deceived them, and that the others were mistaken. The important fact was, however, overlooked by them all that the color of the animal changed with the conditions in which it was placed.

In discussing the principles of breeding, the advocates of

NOTE. The substance of this paper was given in a lecture before the American Association of Breeders of Short-Horns, at their meeting in Cincinnati, Dec. 3, 1873. In its present form it has been extended, and some of the points discussed are more fully illustrated.

each of the extreme views referred to, make their own definitions of terms used, and they are therefore proof against any arguments of their opponents.

On each side men of straw are set up, that are easily demolished when assailed from the standpoint of those who manufacture them.

As discussions based on partial views and unfounded assumptions, are of no practical interest, we do not propose to enter the lists as the champion of the extreme views of either party. The terms in-and-in breeding, close-breeding, inter-breeding, and high-breeding are by some writers used as synonymous, while others make arbitrary distinctions in their meaning that are of no practical significance.

Some use these terms quite loosely,-applying them indifferently to any degrees of relationship, while others make use of them only to indicate the breeding together of the closest relations.

The following definitions of "in-and-in breeding" are selected from the few authors that have defined the term:

The breeding from close affinities.-Youatt.-Johnson.

Breeding between relations without reference to the degree of consanguinity.-Randall.

Breeding from animals close of kin to each other.-Copland.

It should only be applied to animals of precisely the same blood-as full brother and sister.-Bowly.

Breeding from the same family, or putting animals of the nearest relationship together-Sir John Sinclair.

The producing of a succession of animals from parents descended from the same original pair, with which the breeding series, so to speak, is commenced.-R. S. Burn.

Breeding from a near relationship, such as a first cousin, or at the most (one) in the second or third degree.-Stonehenge.

Sir John Sebright, one of our best authorities on the subject of breeding, is often quoted as an opponent of “in-and-in' breeding.

In his work on "The Art of Improving the Breeds of Domestic Animals," he says in his remarks on in-and-in breeding

"Mr. Meynel's fox-hounds are likewise quoted as an instance of the success of this practice; but, upon speaking to that gentleman upon the subject, I found that he did not attach the meaning that I do to the term in-and-in. He said that he frequently bred from the father and the daughter, and the mother and son. That is not what I consider as breeding inand-in, for the daughter is only half of the same blood as the father, and will probably partake, in a great degree, of the properties of the mother."

Although Sir John Sinclair does not formally define the term as he understands it, it is fair to presume from this that he would limit it to closer relationships than those mentioned. It will be found, I think, that the apparently conflicting opinions of writers in regard to this subject have arisen, to a great extent, from the different meanings attached to these terms.

In this paper-without attempting to define critically the terms above mentioned, or to set a limit to the admissible relationships in breeding-it is my purpose to discuss the principles involved in breeding together animals that are closely related, as shown in the practice of those who are generally acknowledged to be the great masters of the art.

In order to prevent any misapprehension of the views here presented, it will be necessary, on the start, to call attention to some of the general principles of breeding.

The breeding of domestic animals is an art, the rules of which are founded almost exclusively upon experience and observation.

The principles underlying these rules can only be mastered by studying the practice of the most successful breeders.

The study of opinions, without reference to experience, will give rise to partial and extreme views, and these in turn will ead to errors in practice.

If we would gain a thorough knowledge of the rules of the art, and apply them successfully in practice, we must become familiar with what has been done by those who have made our improved breeds what they are.