S. M. Zwemer 
Mohammed or Christ, an Account of the Rapid Spread of Islam in All, Parts of the Globe, the Methods Employed to Obtain Proselytes, Its Immense Press, Its Strongholds, Suggested Means to Be, Adopted to Counteract the Evil [PDF ebook] 

Whilst the greatest effort has been made to ensure the quality of this text, due to the historical nature of this content, in some rare cases there may be minor issues with legibility. The following chapters have been brought together and revised at this critical time in the history Of the Moslem world to set forth the appeal of that world for the Gospel. It is a decisive hour! The Old order is changing, and there is a new attitude towards the Old message everywhere. New national responsibilities will follow the great world war and also new Opportunities, especially in the Turkish Empire, Arabia, and Egypt. If this volume awakens a sense of responsibility for the emanei patiou of Moslem womanhood, the uplifting of its childhood, and the winning of its manhood, it will have fulfilled its purpose.