A wide field of discovery and invention still remains unexplored in the department of musical instruments. It is well known that musicians make a distinction between those musical instruments which permit of .perfect intonation and those which are " tempered" or modified in their intervals. The latter include organs, pianos, and melodeons. Such instruments are not, however, to be regarded as seriously defective on this account, although it would iJe desirable to so improve them that perfect intonation could be obtained. Indeed this has been attempted and with considerable success too, but for some reason the improved instruments have not enjoyed large popularity. As a rule those instruments which are of the simplest construction, are the most perfect in tone, and at the same time most difficult to play; as examples we may mention the violin family, large and small, the base and tenor trombones, French horns, etc. The bugle group of instruments which comprise* the opheclides, as well as the key bugle, are fine instruments and capable of very fine effects, both in tone and execution. But they are deficient in what musicians c&Wpor-tamento in singing, the gliding by insensible gradations from one tone to another; one of the most charming musical effects when delicately performed with the voice, violin, or trombone. This defect is common to all keyed instruments, if we except the flutes, upon which gliding from one tone to another can be partially attained by a skillful performer. Valve instruments while they are equal in quality of tone to brass keyed instruments; are deficient in power of delicate I execution, especially in rapid scale passages. The long distance through which the fingers have to move in order to work the valves, produces in a rapid passage more or less slubbering, according to tlie degree of skill possessed by the performer. i Notwithstanding this defect is added to the defects of the keyed instruments by the substitution of valves for keys upon brass instruments, valved horns have attained unprecedented popularity on account of the ease with which they may be learned. There is no doubt in our mind that a more efficacious device can be made for these instruments than the latest j improved valves, one that will combine all tho advantages of valves with none of their defects. But, leaving the J.d beaten jptreh, there are many bodies, capable of emitting under vibration the most beautiful sounds, that have never yet been practically utilized for instrumental purposes. Among these we may class glass, shells, and bars of wood and steel. Of all these rude and imperfect instruments have been made. Dr. Franklin's " armonica" was probably the most complete instrument ever constructed with glass It j consisted of a nest of hemispherical glasses of different sizes, tuned and arranged on a revolving spindle impelled by a treadle, and the tips of the fingers being applied to the edges of the glasses produced the tones. It has always seemed to us that this instrument might be improved by the addition of a finger board and action, and developed into one which would not only have considerable power and facility of execution but also retain its marvelous sweetness of tone. We have seen rude instruments made of steel bars suspended on frames which give peculiar orchestral effects. The well-known steel triangle is an instrument of very limited capacity. The bars of steel united at one end, used in music boxes, produce very pretty effects. The latter are the most perfect steel instruments yet devised. We have seen instruments made of bars of wood laid upon wisps of straw and beaten with cork hammers like the dulcimer, which produced very good tones and permitted considerable execution by a skillful performer. One of these with a harp accompaniment, well performed, is worth listening to. We have seen oyster shells substituted for the wooden bars with good effect. But to return to the instruments already in popular demand for parlor, street, and orchestra. There yet remains much to be done with many of them ere they can be said tq fully meet all requirements. The piano should be made to sustain its tones longer especially in the upper part of its scale. The celebrated Ole Bull has attempted this improvement with only very partial success, if the critics are to be believed who heard its performances at that artist's recent concerts in this city. The melodeons, albeit improved so much during the past twenty years, that they are as far removed from the original instruments as man is from the ape, still admit of much improvement. Their tone is yet very much inferior to that of the pipe organ, and although they are extremely useful, and we may say in the present state of musical requirements almost indispensable, the tones ot the reeds are still so inferior to those of pipes, as to warrant the prediction that large improvement is yet to be made in this family of instruments. IT is stated that a Parisian glassmanufacturer has produced glass threads, so flexible and tenacious that they have been I used in sewing machines.