duced into New York the past summer, a first lot of twenty-five electric cabs being equipped with them June first. Two hundred such cabs will be in operation by winter, and fifty new gasoline cabs that are being imported from France for the public service in New York will also be fitted with them. These are all to be operated by one company that has been in the motor cab business for the last ten years. Several newly organized companies are also preparing to put taximeter cabs in the public service in the metropolis, and one at least contemplates giving similar service to Boston, Philadelphia and Chicago.

The taximeter is a complicated piece of mechanism. It is operated both by clockwork and by a flexible shaft driven, like an automobile speed indicator or dashboard odometer, from one of the road wheels of the vehicle. Since public cab fares are paid on the basis of time consumed and distance traveled, it is necessary to compute both. When the cab is standing, as when for making calls or shopping, the taximeter is operated by the clockwork, but when the cab is under way the flexible shaft drive overruns the clockwork and turns the circular dials that do the registering. The dials are rotated by a train of small spur gears as in a cyclometer or mechanical

counter.

On the face of the instrument there is a small opening which shows the "tariff." When the cab is not engaged this space shows blank. If the vehicle is engaged for one or two persons, a figure 1 indicates that the device is computing at the single tariff; if for three or four, a figure 2 appears. When the vehicle is discharged, the word "Payment" appears. This dial is moved by the driver, who turns it by means of a small handwheel at the back of the instrument. Attached to this wheel is a short staff carrying a metal flag bearing the word "Vacant." This flag stands upright when the vehicle is not engaged, and the wheel stops the clockwork, which remains idle until the vehicle is hired and the driver turns the flag down out of sight, bringing the tariff figure into view. The clock then continues to run until it is stopped, when the passenger dismisses the vehicle and the driver turns up the word "Payment."

minimum charges, and are for the first mile. Thereafter an additional charge of ten cents is indicated for each fifth of a mile under tariff 1, and twenty cents under tariff 2. When the vehicle is kept waiting the clockwork keeps the gears moving and registers an additional ten or twenty cents for each six-minute period that elapses.

In addition there is a dial on the face for "Extras." This dial is controlled by the driver, who turns it to register twenty cents for each mile or fraction thereof that he has to drive the vehicle empty to the point ordered, or to register a charge of twenty-five cents for a trunk carried on the roof.

On the back of the taximeter are other dials, controlled by the same mechanism, where are registered automatically the total distance traversed, the number of individual fares collected, and the individual and total amounts of fares paid.. These records are for the information of the company owning the vehicles, and cannot be manipulated by the driver. The dials may be reset at the end of each day or week, as desired.

HE method of extracting stones by means of wedges driven into them at intervals, or by explosives, is beginning to be discarded in quarries in favor of new processes. The system of sawing by helicoidal cable is becoming more and more widely employed, as it is found to be most satisfactory. Utilized at first for forming an entrance to the lower part of strata in working shafts where there existed no entrance with natural slope, it is employed at present for cutting out stone at the shaft of quarries and forming it into blocks. For guiding and carrying the cable, use is made of a tubular support provided with two channeled pulleys, one of them mounted upon a fixed support at the upper part, and the other upon a movable one sliding along the entire length of the tube. The displacement of the movable support is effected. by a long screw parallel with the tube and which gives the wire the pressure necessary for the sawing of the stone. For the sawing of a detached block, the mounting of these tubes on both sides of the block is done very easily. But the case is entirely different when it is desired to saw into a stratum in which no break occurs. In such an event shafts about thirty-six inches in di

ameter designed for the reception of the tubes are formed at the extremity of the length that it is desired to saw. In hard stone the shafts are driven at distances varying from thirty-five to fifty feet, while if it is a question of soft stone they may be driven at a distance of one hundred and twenty feet from each other.

One of the accompanying illustrations shows a special drill or circular cutter, actuated by an electric motor, and used for the sinking of shafts.

The essential part of this machine consists of an iron plate cylinder, at the

base of which is mounted a knife twelve inches in height. The knife also is cylindrical and upon its lower part are formed alternate teeth upon concentric circumferences. This arrangement of teeth in two rows permits the knife better to attack the stone, and to widen the space in which the cylinder moves. After the shaft is driven, the cylinder and the internal core of stone may be removed.

The cylinder and knife system receives a circular motion of fifty or sixty revolutions through the intermedium of a square rod to the upper end of which is keyed a helicoidal wheel, which engages with an endless screw upon the shaft of the electric motor. The axial reaction of the endless screw is produced upon accurately calibered steel balls. The square rod, through a sleeve, carries along the cylinder, and permits it to descend in measure as the work advances. The weight of the iron plate alone causes the descent of the knife. The sleeve is held in the axis by a movable guide sliding in three uprights of U-iron, forming the frame of the apparatus, in this manner.

As the entire apparatus has often to be shifted, the motor is in no wise sheltered, and so it is of the hermetic type. It is from twenty to twenty-five horsepower.

When the operation of boring is finished and it is a question of removing the cylinder and the internal core, a hand windlass fixed to one of the uprights of the frame is employed. This windlass takes the cylinder by the upper part, while as for the core, a hook is first inserted therein, after which it is broken by driving wedges into the groove formed in the drill.

When it is desired to bore deep holes, a second cylinder may be superposed; and sometimes even a third and fourth are added. In this way shafts of fifty feet in depth have been sunk. As a general thing, however, the boring is not done to a depth of more than twenty-five or thirty-five feet.

The advance of the work varies greatly with the hardness of the stone.

The full page illustration shows portions of a granite core extracted with this circular cutter.

-EDWIN MARKHAM,