makers, and should feel lost without them. There is no occasion to alter one. All sizes are ready to the hand, and they are especially useful for tubes or holes that have to be threaded.

The sizes and styles of the Morse drill and chuck are as follows:

A set of 21 drills, with taper shanks from to 14 inch in diameter, embracing every size usually required by machinists. These drills are made of the best cast steel imported, made expressly for the purpose, and are fitted to sockets that accompany them. Three sockets are required for the set, are made either of steel or iron, as desired, and are readily fitted to any drilling machine. They are of standard size and taper, and consumers are assured that all taper shank drills hereafter made will fit them.

A set of 15 drills, styled the "Machinist's set," of sizes varying by 32ds from 1-16 to 1-2 inch, made of the best material, with straight shanks the same size as the drill. An adjustable chuck (2 inches in diameter), capable of holding every drill, can be furnished. This is easily and cheaply fitted to any lathe.

A set of 29 drills, styled the "Jobber's set," of sizes varying by 64ths from 1-16 to 1-2 inch. This set is especially designed for trades doing fine work, as they will drill the size of the body of screws up to 1-2 inch, and are tap drills from

3-32 to 9-16. The adjustable chuck will also hold this set.

The "Wire Gauge set," comprising the sizes of Stubs' steel wire gauge, from No. 1 to 60, inclusive.

The "half set," by steel wire gauge, comprising

alternate numbers, from 1 to 60; and the "Jeweller's set," consisting of 36 drills, from inch (No. 30) to No. 65 steel wire gauge.

The five smaller sets are neatly mounted on stands, numbered so as to show at a glance the size of every drill, greatly facilitating the selection of the one required for use.

The other drill is the Manhattan Fire-arms Company of Newark, New Jersey, and is in wide demand.

Here is a pin drill (fig. 12), some call it a counter-borer, but this is not a term which can be applied indiscriminately, for in some jobs the tool is used wholly as a drill, and not as a cutter or tool to counter-bore, or drill against certain other holes. The use of this tool is to drill large holes more correctly and faster than a single drill could do it, and it is used the same as any other drill, with this exception, a hole must have previously been made

Fig. 12.

for the "tit" or pin, in the work to be done. If this first hole is not straight the pin drill will not go straight, for the pin follows the first hole, which is usually small, in about the same proportion as the diagram. The first hole acts merely as a guide for the pin, and when it is made true tne pin drill follows in it, and takes out great curling chips of metal with the greatest facility. The pin should have very little clearance in the first hoie, so that it cannot shake about, and the first hole is sometimes a trifle smaller, and the "tit" on the drill is serrated, as shown in fig. 13, so that it clears itself as it goes down, and always fits snugly. If the first hole drilled in the work is too large, the pin drill goes all over, and neither makes a round hole or a true one. These drills are costly to make, as they must be turned in the lathe and afterward filed up, since, from their conformation they cannot be ground on the stone, although they may be sharp

Fig. 13.

ened on a true running stone, when held by a steady hand.

The Morse Twist Drill and Machine Com. pany's Works are at New Bedford, Mass.

CHAPTER II.

THE DRILL AND ITS OFFICE-CONTINUED.

THERE is an endless variety of counter-borers or pin drills adapted to every class of work, but as the principle is the main thing, it is not necessary to follow or to illustrate every one. The counter-borer in one shape is used to cut out the tube holes in flue sheets, which in boilers as lately built require a great deal of time; if the tool is not properly made, many sizes are required in large shops, where much work is done.

Here is a plan (fig. 14) for an expanding or an adjustable tool by which holes in flue sheets can be made of any size, varying only with the plan of the cutters. The apparatus is very simple, and by altering the shape of the cutters, a hole but lit

Fig. 14.

tle larger in diameter than the rod or shaft that carries the arm can be made. The advantages of this appliance over an ordinary drill, such as is frequently used, are that the cutter, which breaks often even with the utmost care, can be easily dressed when