The Largest Belt in

the World

IN the equipment of a saw mill at Tacoma, Washington, the largest single leather belt in the world has been installed. It was made from pure oak-bark tanned leather; is eighty-four inches in width, 114 feet in length, three-ply in thickness, and weighs just 2,300 pounds; it took the centers of the hides of 225 steers to make it, and each piece of this leather was separately stretched before being placed in the belt.

In putting the belt together no pegs, rivets, or fastenings of any kind were used except cement, and the plies were cemented together under a hydraulic pressure of 250 tons. As no hide will produce a single piece of leather wide. enough to make a belt of this width, it was necessary to use two or three centers to make it. These pieces are cemented together, a two-inch longitudinal lap being used. This lap was made entirely by hand. As there was about seven hundred feet of this work, it required a considerable space of time. The finished belt has the appearance of a single piece.

THE EXPLOSIVE, HATHAMITE, HAS CUT A PIECE OUT OF CENTER OF PLATE.

REMAINS OF SHELL AFTER ITS CHARGE HAD BEEN EXPLODED.

Saw mills are operated under widely varying loads, so that the service required of the driving belt is most severe. Any piece of leather, therefore, used for this purpose must bear the maximum strain of the saw mill, for this maximum is often reached.

The pulleys used have broad surfaces. to give the necessary adhesion for delivering the required horse power.

Effects of Explosives THAT explosives sometimes produce

curious effects on metal is a well known fact, but it is seldom that a hole is blown in a piece of steel in such a shape as is herewith shown. To test the destructive properties of the explosive known as hathamite, an ounce of it was placed on a steel plate about an inch in thickness, the plate in turn resting upon a cylindrical piece of iron bored through the center. After the explosion it was found that the hathamite had cut a piece out of the center of the plate the exact

size of the hole beneath, indicating that the force of the explosion had been directly downward. In another test a steel conical shell was filled with the substance and exploded, the shell being blown into the fragments shown in the illustration.

Reckless Fire Losses DURING the year 1906 there was ex

pended in the erection of buildings of all kinds in the United States the stupendous sum of $604,960,000. Enormous as this sum is, however, the building operations for the year were not so extensive as had been expected by architects and other experts, showing an increase of only a little over two per cent above 1905.

The most interesting feature in this connection is that this vast sum is but little in excess of the losses by fire during the same period, these losses amounting to over $500,000,000-it thus appearing that approximately one building is burned for every one erected.

It is asserted by many high authorities. that at least ninetenths of the fire losses in the United States are preventable, and that more than one-half are due to gross carelessness and false economy on the part of builders and owners. Moreover, there is no reason to hope that future years will show any decrease in the amount of fire losses, as the tendency seems to be to provide firefighting appliances and to pay high insurance. rates, rather than to build in such a manner that the danger of fire

will be reduced to a minimum. It is claimed that had one-fifth of the five hundred million dollars lost through fires last year been expended in protecting the steel frames of buildings with hollow fireproof tile, windows with wire-glass, closing off stairways and elevator shafts, and taking other reasonable precautions against fire, the half billion dollars' worth of buildings erected during the year would be practically immune. Under present conditions, every year sees the building of a fuel-pile for another.

While it is generally assumed that all new and modern buildings are of the "fire proof" type, as a matter of fact but two and one-fourth per cent of the structures erected in 1906 are even moderate

A

Strange Growth of
Palm

LONG the shores of Florida lakes and rivers it is not unusual to find the cabbage palmetto growing as seen in the photograph. The example here. shown is an excellent one, as the cause of the phenomenon may be clearly distinguished. The roots of the tree are very small and short, seldom over a foot in length, and are attached directly to the base of the trunk in thick clusters. Thus the tree grows almost on the surface and when the wind and water wash away the beach it is uprooted and falls over on the side. So tenacious is it of life, however, that it continues to grow and flourish, and trees may be seen in which the perpendicular portion of the trunk is longer than the horizontal. The palm shown in the photograph has just begun its course upward, but there is nothing to prevent its growing in that position for years to come.

Unusual Tree House THIS is the season of the year when the landscape gardeners in the employ of the wealthy are able to show the results of their skill in contriving quaint

a single bole.

and unusual features upon the extensive estates under their care. For the past few years it has become quite common to erect big, roomy summer houses well up in the branches of widespreading trees or among the singular duplicate trunk formations of such trees as the chestnut, which, when once cut off at the root, grows again in from three to half a dozen trunks where originally there was but

These tree houses, or tree rooms, intended either as playhouses for children, or as novel, shady summer houses for their elders, where tea may be served in a social way or summer reading or fancy work enjoyed, are locally known as "crows' nests" to distinguish them from summer houses erected on the ground.

The accompanying illustration shows how a group of seven second-growth frame-work of a "crow's nest" on an eschestnut trees were made of use for the tate which has remained in one family since the days of William Penn in the suburbs of Philadelphia. The seven trunks compare favorably in size with those of many single-trunk trees on the estate, and one trunk has been left with its original branches attached to provide shade round about the "nest." A quiet and cozy retreat is well assured.

STUMPS OF SEVEN CHESTNUT TRUNKS UTILIZED FOR SUMMER HOUSE.

Self-Registering
Target

A SELF-REGISTERING target that

does away with the human marker and his mantelet protector, is the invention of Col. George A. Peters of Toronto, Ontario. Electricity is the agent employed for the purpose. Hammers behind the target receive the impact of the bullets. The hammers in turn close the circuit, whereupon a dial registers the result.

The illustrations will give some idea of the mode of operation. The hammers. rest against the back of the target, which is subdivided into a number of independent sections. When one of these is struck, the hammer affected beats back upon the plate, contact being made by projecting lugs. By a push-button conveniently placed with respect to the marksman's position, when a shot has been recorded, the target is promptly made ready to register the next shot.

PETERS' SELF-REGISTERING ELECTRIC TARGET. Iron plate across bottom prevents damage from bullets aimed too low.

Where sections overlap and two or more hammers respond, as many registrations are made as there are hammer beats. The relative position of the disks on the indicator show at once where the bullet found its mark.

Scotland Yard, the famous London detective bureau, has no telephones in its offices.

INTERIOR MECHANISM OF SELF-REGISTERING ELECTRIC TARGET.

Face of target is divided into a number of independent sections which transmit force of bullet impact to

hammers here shown, and operate the
signaling device.

Study "While You
Sleep"

THE

'HE college student who has more money than inclination to study will welcome with delight the appearance of the reported invention of Edward Jacobson, a student at the Northwestern University. This invention is said to be a machine of a phonographic nature for which records are prepared containing, in condensed form, the essential points of an entire course in a particular study. All the student has to do is to select the record relating to the study in hand, light his pipe, turn out the light, lie down on the couch or bed, pull a cord which is attached to the machine and learn his lesson by the roll.

The machine for studying "while you sleep" is constructed with an appliance on the order of the movement of an eightday clock, which, when wound up, will run for a period longer than the listener will survive. Should the student drop into slumber, the constant and monotonous repetitions of the record will have the beneficial effect of impressing the lesson on the apparently dormant brain.

Necessity is assuredly the mother of invention. The student, tired and worn by late hours, may now absorb knowledge with a minimum of effort. It is a royal road to learning.