Viewing page 50 of 313

464
THE TECHNOLOGY REVIEW

PRINTS - THEIR USES AND ABUSES
(Concluded from page 462)

that is clouded or obscured by contradictory accounts might be cleared had there only been pictorial recorders of events as they occurred.

Yet we are thankful for what we have and collectors of these story-telling prints will agress that there can be no greater thrill than the acquisition of an unknown or rare piece that sheds some light upon a point in controversy. Some of us collect naval, marine, and military prints - some turn to those which bear upon scientific or industrial development. Others find their metier in political and territorial material, or search with unwearied anticipation for portraits of the famous of all times and stations. One thing is sure, "as sure as death and taxes": for every print that deals with human activity in any form there is somewhere a collector. Both millionaire and manual laborer are subject to the inherent craving for pictures of one kind or another and once an addict - always an addict. There is no escape.

_____________

DYNAMIC LOADS

(Concluded from page 435)

this condition will be true. But when such an increase in physical strength is accompanied by radical changes in the structure of the materials, so that the fatigue limits detemine the extent to which the load can be increased. A notable example of this is the behavior of certain bronzes used for bearings and worm gears. The best bronze here is the one which has the highest physical strength without any loss of malleability, or the ability to be cold-worked without surface failure. A relatively soft bronze will be cold-worked in service, hardening and increasing the actual physical strength of the surface of the material, whereas a harder and stronger bronze will not cold-work, and its surface will start to disintegrate under load without any appreciable increase in hardness. Furthermore, because of its structure, the size of the released particles of material will be larger than those released from the softer material and will thus cause more destructive cutting than those from the softer bronze.

To sum up: The maximum dynamic loads on rubbing surfaces of mechanisms are impact loads, their intensity being the sum of the transmitted load plus an increment load which is practically a constant for any given speed condition on any given mechanism. The stresses set up by these impacts must not exceed the fatigue limits of the materials if excessive wear is to be avoided. A margin of safety would appear to be a more logical value to use in such cases than a factor of safety. Dynamic loads are not directly proportional to the transmitted loads, hence the use of velocity factors is incorrect and misleading.


ASHBURNHAM SCHOOL FOR BOYS
9 to 16 years of age. Handwork, music, nature study, sailing, horseback riding, real country life all used in a modern way in the boy's education. Summer Camp.

Address HARRY ROBINSON DANE, Headmaster
Box V, Ashburnham, Massachusetts



Meet M.I.T. Men Here

The Technology Club has its headquarters in New York at the Allerton - 38th Street and Madison Avenue. You can always count on meeting M.I.T. men and men from other colleges at the Allerton Houses in New York, Chicago and Cleveland.

College men like the atmosphere. They like the idea back of Allerton Houses... :Live in NINE Rooms... pay for ONE". The comfort and sociability of an exclusive club without initiation fees or dues.

You pay for your bedroom... and at one or more Allerton Houses you have the use of comfortable Lounges, Reading Rooms, Solariums, Roof Garden, Squash and Tennis Courts, Gymnasium, Exercise Rooms, Showers, Billiard Room, Indoor Golf Course, Library and Restaurants.

Stop for a night.. or live at an ALlerton House for economy, comfort, sociability. Select the one that suits your convenience,,, all will suit your purse.

Rates: $12 to $20 a week
Transient Rates: $2.50, $3.00

ALLERTON
Chicago  New York  Cleveland
Please note that the language and terminology used in this collection reflects the context and culture of the time of its creation, and may include culturally sensitive information. As an historical document, its contents may be at odds with contemporary views and terminology. The information within this collection does not reflect the views of the Smithsonian Institution, but is available in its original form to facilitate research. For questions or comments regarding sensitive content, access, and use related to this collection, please contact transcribe@si.edu.