Elementary Studies  is H. L. Clarke's book for beginners.

Introduction

During my career as a cornetist, I have given many thousand lessons to cornet players, from beginners to the best players in the country. Many cornet methods, all good, useful and highly recommended by me are available, but in this work I have had the beginner in mind. It is my purpose to help him lay a solid foundation by means of simple exercises, easy to play, without strain of any kind, and in this way assist him to reach the highest mark of perfection for which we are all striving.
If practiced in the proper way at the start, correct cornet playing is no more of an effort than ordinary deep breathing. To form the lips for producing a pure tone, to train the muscles of the face gradually without noticeable fatigue, to acquire endurance?all of which must be attained before one can become a successful cornet player is the object of this series.
Many of the published methods do not treat sufficiently of the very beginning for those who have never produced the first tone upon a wind instrument, consequently I undertook to write a series of exercises in simplest form which will neither fatigue nor strain the student. Their further purpose is to gradually build up the strength of the facial muscles, to purify the tone without causing the usual weariness so common to most beginners, and finally to acquaint them with a knowledge of those fundamental principles most necessary for cornet study.
In the first place the Cornet is not such a difficult instrument to master as is supposed, if one commences in the proper way at the start. In more recent years obstacles have been overcome with ease that seemed impossible at the time the instrument was introduced. Manufacturers throughout the world have employed experts whose experiments have extended the range of the instrument, improved the intonation and perfected the mechanism, making possible the playing of music written for the voice, or for the Flute, Oboe, Clarinet or Violin, although the compass of the latter is beyond that of the Cornet.
This elementary work is divided into lessons, graduated so as to build up the "embouchure" without physical strain on the student. “Embouchure" is a term applied to the formation of the lips covered by the mouthpiece, the vibration necessary to produce the tone, and the training of the muscles of the face used in contracting the lips for a high note and relaxing them for a low note.

Hints

Here are a few hints, not rules, that years of experience in my professional work have taught me, which if followed out enable the student to build up the "embouchure" without any noticeable strain.
"Always try to produce a musical tone from the very start." Even if it requires time to perfect this, exert patience.
 "Always play softly, never harshly." Remember that the softer one plays when practicing the stronger the "embouchure" becomes, enabling the player to endure more than with the old way of resorting to brute force, which in a short time will destroy the nerves of the lips, the lips become numb.
"Always remember when the least fatigue is noticeable to rest a few moments, even if in the first few minutes of practice." To play a moment after the muscles are tired will place the student back even after weeks of work. A piece of string wound tightly around the finger produces numbness. To press the mouthpiece constantly against the lips produces the same effect upon the lips, which is harmful. Bear this illustration in mind and you will improve gradually and save your lips from breaking down.
"Never hold the lips rigid, but keep them soft and pliable, using only enough pressure to keep the mouthpiece firmly against the lips without the least air escaping outside the mouthpiece."
"Many students want to play solos after taking a few lessons when they know they are undertaking an impossibility." This is like the would-be athlete trying to run a hundred-yard dash in ten seconds without preparing himself beforehand by training. As an illustration, "Don't try to run five miles at the rate of a hundred yards in ten seconds."

Position of the Mouthpiece on the Lips

Take the Cornet in the left hand, grasping the valves gently, the instrument seemingly resting on the hand, which balances the Cornet properly. The first three fingers of the right hand are placed over the keys. Hold the Cornet in a horizontal position.
Place the mouthpiece in the middle of the lips in the easiest and most natural position as the two lips will vibrate equally in the center of the mouthpiece; neither two-thirds on the upper and one-third on the lower, nor one third on the upper and two-thirds on the lower, but in the center. In time this will produce an even tone with volume throughout the entire scale.
There are several positions advocated in cornet methods that contradict one another, but I have always found the easiest and most natural way to be the best for all.
Always keep the Cornet in a horizontal position, neither pointing up or down. Should a player's upper jaw protrude, throw the head backwards a little, and if the lower jaw protrudes, lower the head.
There is nothing more disagreeable looking than a soloist standing before an audience, pointing the instrument at the footlights instead of straight in front of him. The proper position should be acquired in the very first practice. Stand before a looking-glass to get the proper position and you will "see yourself as others see you." The looking-glass is an excellent "fault finder."

Commencing the Tone

When the mouthpiece is placed in the proper position on the lips, then pronounce the syllable "tu," softly at first. The tongue should be placed at the base of the upper teeth, naturally, and as this syllable is pronounced it performs a backward movement resembling the action of a valve.
This pronunciation determines the striking of the sound. Practice it easily, never in a rigid condition, and the tone will come clearer. Never allow the tongue to come between the teeth, because it is impossible to articulate distinctly or rapidly in this manner and the syllable "tu" cannot be pronounced with the tongue in this position. If you try to produce this sound with your tongue between your teeth, instead of at the base of the upper teeth, you will find a sound similar to "thu," which is wrong.

Method of Breathing
"Common sense teaches us more than all else."

Without air or wind there is no tone. Always commence a tone with the lungs inflated, or properly filled, and utilize all the air before inhaling again. Your lips may be perfect, your tongue in the proper position, but no tone can be produced without wind, any more than a locomotive, built perfectly in every way, can expect to move without steam.
Be careful to breathe regularly, inhale with freedom and exhale carefully, never forcing the tone, but producing it naturally. In time you will realize that developing your chest, equalizing your power or generating it, arc important factors and that the lips alone do not play the Cornet but onlyact as the vocal chords in the throat of a singer, which if strained will ruin the success of any vocalist.
Never abuse the lips by straining or pressing them and they will last a lifetime, growing stronger instead of weaker as the hours pass in diligent practice.

"Well begun is half done."